TWI396824B - Method and device for optically measuring the surface of a product - Google Patents

Description

Method and device for optically measuring the surface of a product

The present invention generally relates to a device and method for measuring and inspecting a distance between a sensor and a product under test, which can be used for measurement and testing on a printed circuit board (PCB). Or the field of electronics at the location of components on a solar cell product, or the location of connectors for inspecting electronic components (such as ICs, capacitors, transistors, resistors, etc.), or mounting electronic components on a The position of the reflow solder paste previously used for reflow soldering on the PCB. The invention is preferably applicable to PCB products, solar cell products, such as solar cell wafers or solar cell components and other articles that require flatness measurement, so as to specify their quality, and can also be used to test the surface of the product surface. Roughness. The present invention can also be used to inspect a three-dimensional form of a plurality of articles when scanning an image without having to perform scanning operations from a plurality of locations, which is particularly advantageous in high production processes, i.e., in the need to test surface roughness In the program of degrees and defects, etc.

From current state of the art technology, such surface height measurements are most frequently performed by means of a lightning ray and a high speed camera, preferably using a laser triangulation technique. The lightning ray is directed to the surface being measured, and the camera (which is guided below the specified angle) records the contour of the measured area in a landmark (in a position) such that the laser illuminates it. Individual images are recorded at a frequency corresponding to the width of the laser beam and then all images are composed. Use this program to form a 3D model.

Another method uses a variety of cameras that are directed from a variety of angles to the area of the test. A 3D model can be formed from the known trigonometry of the camera in the tester.

A further method uses the Moiré effect, by means of which the morphology of the test area can be made visible in some cases. The image is produced by two grids that are always in opposite brightness. After the two images are combined, the surface topography is reflected when an interference effect is used.

Document WO 02/082009 A1 teaches a method and a device for measuring the distance between a sensor and a product using the color information of the light reflected by the object. The color distribution of the three-dimensional surface is related to a height level of the surface of the object such that color information can be used to analyze the three-dimensional structure of the surface of the object. The white light source can be a combination of a tungsten lamp or a plurality of multi-color sources having a plurality of beams of a single wavelength.

From JP 61 075210 A, we can learn a range finder device in which the light of a light source is diffracted into a multi-color beam to illuminate one surface of an object. The signal intensity ratio of the light reflected by the surface of the object filtered by two different filters can be used to measure the angle and distance between the surface of the object and the camera.

Finally, JP 7 117 399 B discloses another distance sensing device that defines the most current state of the art.

Methods known from current state of the art techniques do not allow obtaining surface height information having an accuracy of less than +/- 20 μm. In addition, a maximum scan width of a tested product is limited, making it impossible to scan products wider than 150 mm. The scanning speed is limited, thus making a high-speed production process The surface measurement reaches a bottleneck.

Summary One object of the present invention is to provide a method and apparatus for measuring and inspecting the surface of a product with high accuracy, high speed, variable measurement resolution, and an increased y width. Moreover, it is an object of the present invention to provide a method and a device for performing an automatic calibration, thereby eliminating the task of high precision structural construction and complex calibration.

The problems of the current state of the art mentioned above are solved by a device and a method according to the independent technical solution. Advantageous embodiments are the subject matter of the accompanying technical solutions.

The present invention provides a device for optically measuring the surface of a test product capable of performing an inspection of a surface of a product, a component alignment inspection or an inspection of a solder paste configuration prior to a reflow soldering process, and capable of An optical 3D model of the surface of the product is created. The device includes the following components:

A white light source that advantageously emits a white light beam having a continuous spectrum. The light is aligned by a collimating unit (including optical components such as lenses, aperture members, etc.) into a parallel, narrow, and collimated beam that is then passed through a spectrometer unit, which is preferably an optical稜鏡 or a diffraction grating. Preferably, the aperture member includes a slit aperture for producing a flat and wide expanded white light beam.

A spectrometer unit, in particular an optical unit, decomposes one of the white lights into a multi-color beam comprising light of a wider frequency spectrum. The multi-color light entering the 含有 contains the selected or all of the white light Color composition. After passing through the spectrometer unit, the white light is decomposed into individual colors according to the law of light refraction. The individual components are monochromatic with different tonal values, such that the multi-color beam comprises a spatially distributed spectrum and illuminates the surface of one of the products under test in a scanning direction. The width of this spectrum directly affects the measurement accuracy of one of the z-axis heights of the surface of the product.

A first camera, preferably a one-line scanning camera. The camera progressively records the surface being tested progressively while the product is moving relative to the camera in an x-axis scan direction. The geometric position of the camera and the source remains the same throughout the recording. The camera and the light are adjusted line by line to zero height (ground) such that the camera displays the beginning of the spectrum, i.e., red. All non-zero heights are then displayed in another color within the color spectrum. It should be noted that in this test the product moves relative to the white light source, the spectrometer unit and the camera, or the white light source, the spectrometer unit and the camera move relative to the product under test.

In other words, a device for optically measuring the surface of a test product (especially one of the PCB product inspections for reflow solder paste inspection) includes at least one white light source for emitting a white light for collimating the white light beam At least one collimating unit, at least one spectrometer unit, preferably an optical chirp or an optical diffraction grating, to split the white beam into a beam of multi-color light at a predetermined angle of incidence γ Down to the test product, and at least one camera for recording a reflected beam of monochromatic light of the test product. In this way, one of the z-axis surface height information of the test product can be extracted from the tone value of the reflected light beam of the monochromatic light, and at the same time, an x-axis The scanning direction relatively moves the test product.

In accordance with the present invention, the white light source is an LED strip that is adapted to produce a white strip light beam. At least one microlens is optically coupled to the at least one LED to pre-align the white light beam, and the collimating unit is adapted to collimate the white at 360° with a collimating quality of 3°, 2° or less The light beam is formed to form a white light strip beam perpendicular to the scanning direction and includes at least one lens, preferably a cylindrical lens and at least one aperture member, preferably an adjustable slit aperture.

Therefore, the collimating unit preferably at least aligns the light to a collimating quality of 3°, 2° or less in all directions. In contrast to parallel light, collimated light creates highly parallel beams of all color/tone values. The collimating unit can include an optical alignment member, such as a lens, aperture or mirror, to collimate the light in 360°. From the collimated light, a multi-color spectrum of light is formed by the spectrometer unit, wherein the individual color and/or tonal values are presented in a manner distinguishable from one another. The light can be directed using a light mixing member, such as a aperture or an optical fiber.

Alternatively or additionally, the collimating unit can be placed directly behind a light source and can include a lens that pre-collimates light with an attached mechanical tunnel, wherein the tunnel filters uncollimated light. In this way, the complexity of the collimating unit is reduced, and the length and diameter of the tunnel determine the collimating quality of the light. The tunnel can have an arbitrary cross section, such as a rectangular, circular or elliptical cross section, and its length can be adapted to a desired collimation quality. The light is focused by the lenses into the tunnel and the tunnel absorbs the unaligned portions. Providing a collimated light having a defined opening angle at the end of the tunnel - the radius of the tunnel And length definition. A single tunnel or a plurality of tunnels may be provided such that the collimating unit may include a single tunnel/channel/LED or multiple tunnels/channels/LEDs arranged in a column. It may be advantageous to provide a mechanical adjustment member to adjust the length, height and/or width of the tunnel to adaptively adjust the collimation quality, for example, a telescopic tunnel for varying the length, width and/or height of the tunnel. configuration.

According to an advantageous embodiment, the white light source can have a continuous spectrum. Additionally or alternatively, the frequency bandwidth of the spectrum can be variable, preferably in the range of one wavelength from 350 nm to 850 nm (ultraviolet to infrared). Additionally or alternatively, the intensity of the white light source can be adjustable, preferably by dimming the light source or by selectively switching two or more light sources in parallel to turn on or off.

According to another advantageous embodiment of the present invention, a white light source, a collimating unit and a spectrometer unit can be displayed by an LCD projector, a video projector or another video imaging device capable of generating a multi-color light. A whole. Because the projector typically includes a white light beam, a collimating unit for aligning and collimating the white light beam, and a spectrometer unit, such as a multi-color LCD for converting the white light beam into a multi-color light beam. . A general specification of a multi-color beam, such as brightness produced by an LCD projector, opening angle, width of different portions of the color beam, etc., can be easily controlled by an image control unit to produce resolutions having different color widths. A multi-color beam makes it easy to control a measurement accuracy. In addition, the LCD projector can produce 100 fps (frames per second) or even more to adaptively change the shape of the beam. A projector can be easily scanned with a side or a line A camera combination is provided to provide an embodiment of the present invention.

According to the present invention, the white light source is adapted to generate a white light strip beam, and the light source is an LED light source, preferably an LED strip, wherein at least one microlens is optically coupled to the at least one LED for pre-alignment The white light beam. Additionally or alternatively, the plurality of LEDs of an LED strip can be selectively switched on or off to enhance the intensity and/or length of a white light beam in a y-axis direction perpendicular to the scan direction. Additionally or alternatively, an LED strip can include a plurality of LEDs of different colors to mix the multi-colored light into a white light beam to provide an adjustable frequency spectrum of the white light beam. Preferably, the LED strip comprises one or more LEDs. The LED produces an uncollimated light that radiates in all directions, so the radiation of the light needs to be pre-aligned according to the structure of the LED strip.

The strip can be adapted to a desired scan width so that the device can inspect the product with different y-axis widths. Advantageously, the strip of light can have a width of one of the largest scan widths, wherein the "longer" white beam can be adaptively focused by a non-parallax optic into a "shorter" white beam. For example, the strip of light may have a length of 450 mm to 600 mm in the y-axis direction, and the length of the flat beam of white light may be focused by a non-parallax optic to a length of 150 mm. The z height resolution may be adapted by a variable aperture width, the splitting angle of the spectrometer unit, or the distance of the spectrometer unit from the surface. Due to the variability of the z-height resolution, different scan resolutions can be achieved. The y width of the strip can be enlarged by the use of mirrors, light guiding elements such as optical fibers or lenses, and the like.

A light strip can also be obtained from a standard by using an objective lens and/or a cylindrical lens It is true that the light source is generated. Thereby, the choice of different glasses can adjust different refractive indices and enhance the image without parallax.

LEDs typically produce a non-homogeneous distribution of white light. Therefore, it may be advantageous to mix different types of white or multi-colored LEDs to produce a homogeneous white light spectrum. This mixture can be achieved by using lenses, mirrors, glass fiber optics or the like. In addition, many bands of light can be used in parallel for additional beams to enhance scanning speed.

The quality of the white light can be further enhanced by integrating a polarizing filter element into the white light source to reduce reflection effects, and is particularly advantageous for illuminating metallic/non-metallic surfaces. In summary, the quality of the white light can be enhanced by: ̇ variable pore size; 光谱 spectral homogeneity of the white beam; 无 non-parallax optics for reducing shadow effects; ̇ optical components for y-direction Adjust the length of the strip to the length of the aperture; the intensity control component for adjusting the surface reflection effect; ̇ adjust the length of the strip to adjust the scan width to the product size.

According to a further advantageous embodiment, the collimating unit can be adapted to collimate the white light beam at 360° and can be adapted to form a white light strip beam perpendicular to the scanning direction, and can preferably comprise at least one The lens and/or a collimating grid and/or at least one aperture member is preferably an adjustable slit aperture aperture member.

According to another advantageous embodiment, the device may also comprise a scan transmission structure And transmitting the test product or the light source, the spectrometer unit, the collimating unit, and the camera relatively in a scanning direction.

According to another advantageous embodiment, the camera may be a line scan camera, preferably comprising a camera aperture unit and/or a parallax lens unit to reduce parallax effects, in particular a lenticular lens or a circular lens unit. To receive a monochromatic beam of light reflected from the multi-color beam of the test product. Additionally or alternatively, the camera can be a one-digit camera having at least 8-bit tonal resolution, preferably an adjustable tone resolution of 10, 12 or higher. Additionally or alternatively, the camera may include two or more line scan columns, each column including a color filter for increasing hue sensitivity. Additionally or alternatively, the camera can include at least one gray or black/white scan column to enhance scan quality. Alternatively, the camera can be a side scan camera whereby one or more scan columns of the scan area can be extracted for tone height information processing. This one-sided camera can preferably have 1500 columns or more and can be used for resolutions as low as 20 μm. Advantageously, the camera comprises two or more scan lines having different color filter elements in front of the two or more scan lines, the sensitivity of each scan line being enhanced by the different color filter elements To different tonal values.

In an advantageous embodiment, the camera can be a CIS camera. A contact image sensor (CIS) allows the fabrication of a technique that does not limit the scan width of one of the camera sensors. Contact Image Sensors (CIS) are ideal for use in the field of optical flatbed scanners and quickly replace CCDs in lower power and portable applications. In a CIS camera, the image sensor is placed in almost direct contact with the object to be scanned, which is different from using a mirror to light The situation in a conventional CCD scanner that bounces back to a fixed sensor. A CIS typically consists of a linear array of detectors, covered by a focusing lens, and surrounded by red, green, and blue LEDs for illumination. The use of LEDs allows the CIS to be more power efficient, allowing the scanner to be powered via the minimum line voltage supplied by a USB connection. A CIS-based camera sensor is smaller and lighter than a CCD line sensor and allows all necessary optical components to be contained in a compact module, thus helping to simplify the internal structure of the scanner. The height of the camera can be about 30 mm or less due to a CIS contact sensor. The CIS camera can be added without a space in the middle, and thus inspections in the width of meters are feasible. The sensor moves to the device under test (DUT) and the light (collimated and split by 稜鏡) can be placed as described before crossing the full width. This allows inspection of very large devices with an almost unrestricted width.

Due to the larger y scan width of one of the cameras perpendicular to one of the x-axis scan directions of movement, a scanned image may include parallax related errors. A parallax lens is used in a line of sight between the surface of the product and the camera, but also between the white light source and the spectrometer unit, allowing parallax errors to be corrected, thus enabling 3D scanning of one of the products without higher quality. A parallax lens system should correct for different light diffraction characteristics at all wavelengths. The lens system can include a lenticular lens of length extension, but also includes a circular lens. A lenticular lens can be advantageous when using a one-line type scanning camera.

The degree of z-height resolution is a result of a combination of the reflected tonal value of the spectral light and the color resolution accuracy of the camera. A single CCD chip, multiple CCD chip, CCD line camera or other digital camera can usually be mentioned A color resolution of at least 8 to 10 bits per pixel, typically 16 to 32 bits, especially 24 to 30 bits or more. Adjusting the color resolution of the camera increases the measurement resolution. Scanning with a different number of camera lines can measure the resolution for another possible zoom. For example, a two-line camera can be used, and the camera can focus on two or more different color regions so that a scalable resolution can be achieved. The number of camera lines can also be increased to four or even more scan lines, where different color filters can be assigned to individual camera line columns, thus enhancing resolution accuracy.

A side camera or a plurality of line cameras that can scan a surface area of the test product (instead of scanning a one-line camera that is perpendicular to a x-axis surface of the x-axis scanning movement direction) can also be advantageously used as a scanning camera. . The individual lines of the image produced by the surface area can be extracted into a plurality of scan columns, whereby an increased number of extracted columns can increase measurement accuracy. In addition, a scan speed can be increased by extracting a plurality of scan columns at a time.

A camera may include one or more color sensitive scan columns and at least one white/black or gray scan column. Thus, the black/white or gray scan column can scan a 2D image of the surface of the product to provide the x/y size of the product. The color scan column provides hue information for the z-height of the surface of the product such that the x/y and z-size values of the product can be extracted in a scanning procedure. In particular, if one of the surfaces of the product is full of cracks, a 2D image provides the exact x/y size of the associated z-data to distinguish the surface area of the product.

It may be advantageous to use a camera comprising a processing unit for directly converting the tonal value to a z-height value based on calibration data of a tone height map. Therefore, the processing unit of the camera can directly CCD the camera The material is converted into z-height data which can be transferred to a control unit. In addition, the processing unit can use different calibration routines, such as luminance extraction, RGB conversion of HIS data (hue, saturation, intensity), geometric calibration based on column data capture and column transfer calculations, and the like. Therefore, the camera can directly output z-height measurement data, wherein the camera can provide 3D area data of the scanned product.

According to a further advantageous embodiment, at least two or more cameras can be arranged perpendicular to the y-axis direction of the x-scan direction for parallel scanning, thus enhancing the scan width of the product. Additionally or alternatively, the two or more cameras can be configured for stereo measurement to scan the product in 3D to reduce shadowing and illumination effects. Configuring two or even more cameras in a scan column perpendicular to a scan direction increases the scan width and thus enables scanning of larger products at high speeds. Using a stereo measurement configuration that focuses on one line or two or more cameras on the surface of the product can reduce the shadowing effect, which can therefore increase measurement accuracy.

According to a further advantageous embodiment, the device may further comprise a control unit electrically coupled to at least the camera, the control unit comprising a control member and a tone height mapping member adapted to at least control the camera and mapped by the The camera captures the tonal value of one of the images to obtain surface height information for the product.

According to a further advantageous embodiment, the device may further comprise an adjustment member controllable by the control member of the control unit to adjust the color spectral width d of the multi-color beam, in particular for adjusting an armature of the collimating unit Width w, and / or used to adjust a beam splitting height b, at the source of the light One of the distances between the cameras a or the angle α of the spectrometer unit to adjust the height measurement sensitivity.

Furthermore, it may be advantageous to increase the intensity of the spectral light to place an achromatic lens unit after the spectrometer unit. An achromatic unit or achromatic lens can be a mirror or a lens designed to limit the effects of chromatic aberration and spherical aberration. The achromatic unit is corrected to bring two wavelengths (usually red and blue) into the same plane for focusing. The additional achromatic lens unit can focus the spectral light to a small height so that the height resolution can be generated. The achromatic lens unit can be a final lens (achromatic lens) or can be a convex mirror. A mirror surface can be advantageous in reducing achromatic lens diffraction problems caused by different refractive indices of different light wavelengths. Different mirror shapes can provide different levels of light height, which can also be adjustable, for example, by replacing the mirror. The second aperture unit on the optical path (for example, between two telecentric lenses or before the spectrometer unit or 稜鏡) can further optimize the light quality such that the captured image is in quality Improved, thus simplifying image filtering and speeding up image processing time.

The measurement method of the test product includes the following steps:

校准 Calibrate the color scale of this height with [mm]. This is performed by scanning the region down, wherein the angle of the downtilt is known in advance to have a higher degree of precision. The image of this downdip region will gradually acquire the entire spectrum, and at the same time, the height in the actual region will be known from the geometry of the downtilt region. The function of the dependent color [R, G, B] = function (height) [mm] will be derived from it;

̇ Test the composition of the scanned surface. The image produced by the camera is composed of A separate image that displays all parts of the surface of the test product. The dimensions on the x-axis and the y-axis correspond to the actual dimensions of the recorded item. The color reflection of the item corresponds to its height on the surface.

Next, the software calculates (according to the function obtained during calibration) the determined value of the color component [R, G, B] of the individual pixels of the actual height (z-axis).

In the area currently tested, the software directly reports the height values (eg, the area above the capacitor).

In other words, the method of the invention for optically measuring the surface of a test product using a device according to any of the above-mentioned technical solutions, in particular for the reflow solder paste inspection of a PCB product, comprises the following step: A white light beam is emitted by the white light source, the white light beam being aligned and aligned by the collimating unit until a parallel narrower beam passing through the spectrometer unit, the light beam being split by the spectrometer unit into a color spectrum. The reflection of the multi-color beam on the product or its components is recorded by the camera. While moving the product in a scanning direction relative to the camera, an image is composed of the camera from individual images of all portions of the surface on which the product is displayed, and the dimensions of the image in the x-axis and y-axis directions correspond to The actual size of the product. At the same time, the tonal values of the image, i.e., the values of the color components [R, G, B] of the individual pixels, are assigned to the surface height values of the product.

According to a further advantageous embodiment, the hue value mapping of the hue value of the color spectrum to the z-surface height value can be at least one progressive recording of a surface of a calibration body having a high degree of precision known in advance to one of the calibration angles β. Calibrated, and can be stored in one tone height mapping member In the graph. Preferably, the calibration system is a glass or ceramic plate or disk or is made of a material having an edge.

By scanning the measurement device with a calibration body having a surface down-tilt with a previously known calibration angle β, complex calibration actions can be omitted, such as high precision mechanical adjustment of the device and complexity of determining surface height values. method. One of the complex mechanical calibrations necessary for a resolution of 1 μm or less will result in a very expensive and complicated measurement action and is therefore not available for continuous production methods. The surface height identification is related to the spectral hue of the light reflected from the surface of the product in the test. Because the resolution of the camera pixels is limited, the spectral components of the reflected light are typically mixed. The device can be calibrated by measuring a ramp function of one of the tilting surfaces of a calibration body that is tilted down at a calibration angle β. Furthermore, if the curvature function of the surface is known in advance, one of the calibration bodies can also be used to bend the surface. From scanning a surface topography of a calibration body, a tone height map can be created that can determine a surface height from a measured tone value. To enhance the calibration quality of the device, a calibration routine can be repeated at different calibration angles and/or different calibration body widths, whereby an average tone height map can be calculated based on the results of the different calibration routines. The spectral light components of the different reflections of the surfaces of the different calibration angles can be assigned to different z-height values according to the bending function of the calibration body.

During a scanning procedure, a direct evaluation of the height information can be extracted from the tonal values of the image data (original image data) produced by the camera. Therefore, an instant z-height profile of the surface of the camera of the test can be generated, eliminating any measurement delay, whereby the instant processing can be performed using a one-line processing method. Good land reached.

During one calibration procedure, one of the step widths of the calibration body movement in the x-axis scan direction of movement affects the calibration quality. Selecting a smaller step width or a larger step width determines the quality of the calibration and the z-height measurement resolution so that an SNR ratio (communication ratio) can be optimized. For example, a surface slope of a calibration body having a size of 100 mm × 150 mm × 5 mm (length × scan width × height) can be scanned with a scan step width of 20 μm, which results in a scan data of 5.000 pixels × 7.500 pixels. The quantity, which needs to be stored as a tone height map, and which limits a z height resolution to 5000 height values. Reducing the step width to 1 μm results in a z-high accuracy resolution of 100.000 height values. A further modification of the surface of the calibration body (e.g., following a predefined calibration surface function) may further enhance resolution accuracy. The use of a pre-calibrated tone height map reduces the data processing of further scanning procedures, thereby enhancing scan time and reducing constraints based on the mechanical accuracy of the measuring device. As a result, a continuously produced measuring device that is less expensive and more feasible can be produced.

According to a further advantageous embodiment, the geometric position of the camera and the light source can be stationary throughout the scan, and/or an instant tone height map can be performed using the tone height map during the scan.

According to another advantageous embodiment, the camera can progressively record the tonal value of one of the surfaces of the product progressively while simultaneously moving the camera relative to the product in a scanning direction.

According to a further advantageous embodiment, the camera and the white light can be adjusted such that the start of the color spectrum maps to zero height. In addition or again, remembered by the camera The tonal values recorded can be converted (preferably from a tone height map) to the actual surface height of one of the products or components thereof by means of a calibration function.

According to another advantageous embodiment, a 3D model of the product can be established based on the measured x and y values of one of the images of the camera and the z-height value based on the hue values of the image on the x-axis and the y-axis.

According to another aspect of the present invention, there is provided an application of one of the above-described devices and one of the above-described methods for measuring the size of a product and/or for constructing a 3D model of the product, particularly For measuring and inspecting the position and height of reflow solder paste on a PCB product and/or for measuring the surface roughness of the product.

Surface roughness can be tested using a self-calibrating measurement device with a high z-height accuracy and a narrower width multi-color beam. As a calibrated body, a surface having one of a predefined value of surface roughness can be used instead of a calibrated body having a surface that is lowered by a calibration angle β. Therefore, different calibration bodies having different surface roughness values need to be scanned at different z-heights according to one embodiment of the measurement device to calibrate the device for surface roughness measurement. The extracted tone height map can be used to determine the surface roughness of the surface at different z-height levels.

Advantages of the subject matter of the present invention

The main advantages of the present invention are seen in the solution of the invention of simplicity, resistance and integration. The recording of the image for the geometric test is carried out in one step together with the scanning of the item. If it is not necessary to perform a color test of the area, a 3D test can be directly performed when the image is normally read, which does not extend the test time. It is not necessary to recalculate the 3D model or mold it The type (as in the case of other systems), the height of the item is recorded in the image and can be read directly. After incorporating the existing system, further actions that require time are not necessary, the invention has only minimal requirements according to SW, and it can be used as an additional module in existing devices.

The high degree of variability and availability is derived from the easily adjustable range of measurements by which the required measurement accuracy can be achieved. The extent of the measurement is set by the distance, or by rotating the optical cymbal as the width (and height) of the color spectrum changes, such that the surface of the test is illuminated. Thus, measurement accuracy of a few microns can be achieved for smaller items and their components (measurement range is tens of millimeters - for example, electrical components).

The basis of this equipment is optical components and, therefore, will not cause wear or aging. The only component that has a limited lifetime is a light source; however, there can be variations between operations of hundreds to thousands of hours.

The invention, together with the objects and advantages of the invention, and other objects and advantages are best understood from the following detailed description of the embodiments of the invention.

A first embodiment of a test device 15 for measuring a test product to optically create a 3D model is shown in Figure 1a and includes a white light source 1 having a continuous spectrum of white light, an optical unit 4 for The white light is aligned and aligned until one of the white light collimated beam 30, one as an optical pupil of the spectrometer unit 2, for splitting the collimated beam 30 of white light into a multi-color beam 31, and an RGB line type Scan camera 3. The light of the light source 1 is collimated by the optical unit 4 up to the collimated white light beam 30, which then passes through the optical 稜鏡, The optical pickup is used as a spectrometer unit 2, and the decomposed light is adjusted to the spectrum of a multi-color beam 31 (Fig. 5). The collimated white light beam 30 entering the crucible 2 contains all of the color elements. After passing through the optical pupil as the spectrometer unit 2, the collimated white light beam 30 is decomposed into individual colors of the multi-color light beam 31 in accordance with the law of light refraction. The individual light components are monochromatic because the individual reflected monochromatic beams 32 are emitted by a color spectrum 55. The spectral width d 6 of the color spectrum 55 directly affects the resolution of the distance in the z-axis. The line camera 3 (single column), which is preferably an RGB or at least one color camera 3, progressively scans one surface of the test product 5 progressively in an x-axis scanning direction 9. The geometric position of the camera 3 and the reflected monochromatic beam 32 does not change during the entire scan. The camera 3 and the reflected monochromatic beam 32 are adjusted to zero height (ground) such that the camera 3 displays the beginning 7 of the spectrum 55, i.e., red. All non-zero heights are displayed in another color that is within the color spectrum 55. In order to adjust the spectral width d6 of the color spectrum 55, the pore size of the collimating unit 4 is adjustable, so that the measurement range of the resolution quality and the z value can be adjusted. The test product 5 is a PCB on which a number of electronic components 16, such as capacitors, transistors or ICs, are disposed. The measuring device 15 checks that one of the electronic components 16 is properly aligned.

The manner in which the test product is measured includes a number of steps. The first step is to calibrate the color spectrum for a distance conversion of height. This is performed by scanning a calibration angle β 20 of a surface area of a calibration body 19, wherein the calibration angle β 20 is known in advance and has high accuracy, see FIG. The image of the downtilt region will continue along the entire color spectrum 55, and at the same time, the height of the actual region will be known from the geometry of the downtilt height. Dependent The function of the color [R, G, B] = function (height) [mm / μm] will be derived from it.

The next step is to test the composition of the scanning surface. The image produced by the camera 3 is composed of individual images, which display all portions of the surface of the test product 5. The dimensions on the x-axis and the y-axis correspond to the actual dimensions of the recorded product 5. The reflected monochromatic beam 32 of the test product 5 corresponds to its height on the surface. Next, a software calculates (according to the function obtained during calibration) the determined values of the color components [R, G, B] of the individual pixels to determine the actual height (z-axis). In the actual test area, the software directly reports the height values (eg, the area above the capacitor).

Figure 1b schematically shows a special configuration of the camera 3, the white light source 1, the collimation unit 4, the spectrometer unit 2 and the product 5 under test. The white light source 1 emits white light which is collimated by the collimating unit 4 up to a collimated white light beam 30. 30 of the collimated white light beam of the spectrometer unit 2 by a division into a plurality of color light beams 31, wherein the plurality of color center beam 31 strike the surface 5 of the test product a point P _3. At the point P _3, the reflected monochromatic beam 32 a perpendicular to the flat surface of a test product 5 is reflected to a lens of a camera 3. The optical axis of one of the white light sources 1 strikes the point P ₂ of the surface of the product 5. Point P ₁ defines the collimated white beam 30 to an entry point in the spectrometer unit 2, wherein the collimated white beam 30 is refracted and expanded to a multi-color beam 31. Points P ₁ , P ₂ and P ₃ define a right-angled triangle, wherein an angle γ defines the angle of incidence at which the multi-color beam 31 strikes the surface of the product. This angle γ depends on the height b of the spectrometer unit 2 above the surface of the test product 5 (the distance between the points P ₁ and P ₂ ) and the distance between the optical axis of the white light source 1 and the camera 3 a (the distance between points P ₂ and P ₃ ). By changing a and b, this means changing the angle of incidence γ to adjust a measured resolution value of the surface.

2, 3 and 4 schematically show a measurement of an electronic component 16 mounted on a PCB as test product 5 while scanning the PCB in a scan direction 9. 2 illustrates the reflection of a color spectrum 55 on a smaller sized electronic component 16, such as an IC (integrated circuit). The height of the electronic component 16 is small such that a monochromatic light (red light 10) near the beginning 7 of the color spectrum is reflected.

3 illustrates a reflection of one of the medium sized electronic components 16, for example, a transistor in which a single color from the middle of the spectrum, such as a green 11, is reflected and detected by the camera 3. 4 illustrates one of the multi-color beams reflected by one of the larger electronic components 16 (such as a capacitor). A violet light 12 near the end 8 of the color spectrum is reflected into the camera 3. Thus, a height of an electronic component 16 mounted on a PCB as the test product 5 can be easily measured from different tone values (red, green, purple).

Figure 5 shows a tone height map in accordance with one embodiment of the present invention. Given a specific measurement device configuration, the hue height map relates a range of heights from 0 mm to 10 mm to a spectral range of light from 460 THz to 740 THz (420 nm to 660 nm wavelength). This correlation between wavelength/frequency and metric size can be extracted by calibration routines in accordance with one of the embodiments of the method of the present invention. The color spectrum 55 provided by the spectrometer unit 2 comprises a range of color beams 31 having a range of wavelengths between 350 nm and 750 nm, the wavelength of which corresponds to an optical frequency between 800 THZ and 400 THz. The color spectrum 55 reaches from the beginning 7 of the color spectrum having the lowest frequency (ie, the maximum wavelength corresponding to the color of an infrared light) corresponding to an ultraviolet color One end 8 of the color spectrum, covering a red component 10, indicates a lower height of a device 5 under test, for example, an electronic component 16 or a solar wafer, a green component 11, indicating a medium The height and a purple component 12 indicate a higher height as one of the test products 5 of the device under test (DUT).

6, 7, and 8 illustrate a number of options for varying the width of the color spectrum 55 to control the measurement resolution of an embodiment of the present invention. Figures 6a and 6b illustrate a configuration, one 4 wherein the pore size of the collimating means a pore size varying between a pore size w ₁ to w _2. As a result, the width of the collimated white light beam 30 and the dispersion angle of the multi-color light beam 31 change, and thus the spectral width 6 of the color spectrum 55 changes from the length d 1 to the length d 2 .

Figures 7a and 7b show a similar effect by changing one of the apertures α 18 of the optical pupil of the spectrometer unit 2. In Fig. 7a, an optical aperture has an opening angle α ₁ which forms a spectral width d 16 of the color spectrum 55. By changing the opening angle α ₁ to a value α ₂ , one of the spectral widths 6 of the color spectrum 55 changes from d ₁ to d ₂ . By using a liquid optical cartridge, an optical aperture having a variable opening angle α 18 can be provided, wherein the opening angle α 18 can be varied by different electrostatic potentials or by mechanical components or other techniques known in the art. Adjustment.

8a and 8b illustrate another embodiment of a measuring device 15 in which a height b between a surface of a test product 5 and a spectrometer unit 2 can be varied. By changing a distance b ₁ to a distance b ₂ , the opening angle of the multi-color beam 31 changes, thus causing a variation in the spectral width d 6 of the color spectrum 55 from d ₁ to d ₂ . According to the height of the spectrometer 2 on the surface of a test product 5 from b ₁ to b ₂ , a distance a between the optical axis of the white light source 1 and the camera 3 should also change from a ₁ to a ₂ , thus leaving The incident angle γ is constant.

FIG. 9 illustrates another embodiment of a measurement device 15 in which a calibration routine is performed. A calibration body 19 (e.g., a calibration plate 19) having a calibration angle β 20 that can be adjusted to one of the horizontal surfaces of the test product 5 is mounted on the top surface of a test product 5. While moving the lower surface of the calibration body 19 in a scanning direction 9, the white light source 1 produces a collimated beam 30 which is collimated by a collimating unit 4 and which is split by the spectrometer unit 2 into a multi-color Light beam 31. The spectrometer unit 2 has a variable angle α, and the collimating unit 4 can change a pore size w to adjust the opening angle of the multi-color beam 31 to affect the height measurement resolution accuracy. Due to the movement of the calibration body 19 in a scanning movement direction 9, the different reflected monochromatic light beams 32 are reflected towards the camera 3, wherein the camera 3 is equipped with a camera aperture unit 24 to eliminate parasitic scattered light. The camera 3 scans the light with respect to the scanning direction 9 of the calibration body 19 having a downwardly inclined surface at a calibration angle β 20 and transmits the image data to a control unit 21. The control unit 21 includes a control member 22 that controls the intensity/luminance of the white light source 1, the aperture width w of the collimation unit 4, and the aperture opening angle α 18 of the spectrometer unit 2. The tone data received by the camera 3 is stored in a tone height map 20 of a tone height mapping member 23, wherein the different colors are associated with different z-height values known from the calibration angle β and the size of the calibration body 19.

10a and 10b illustrate a white light source 1, a collimating unit 4, and an optical pupil as a spectrometer unit 2 for generating a starting point 7 (red light) and a color having a color spectrum. A multi-color beam 31 of one end of the spectrum, 8 (violet), impinges on a surface of one of the products 5 under test. Figure 10a shows a side view and Figure 10b shows a top view of the overall. The white light source 1 includes an LED strip 40 (light emitting diode) in which a plurality of microlenses 41 align the diffused white light emitted by the LED strips 40 to a parallel beam. The collimating unit 4 includes a first lens 42, a second lens 43 and a third lens 44, and a aperture member 50, which can be a slit diaphragm. The aperture member 50 is a slit aperture having a variable opening width w such that the width of the collimated white light beam 30 can be adjusted. The collimating unit 4 converts the white light beam emitted by the white light source 1 into a collimated white light beam 30 having parallel beams of white light of all different color values. The optical pupil, which is the spectrometer unit 2, divides the collimated white light beam 30 into a multi-color beam 31 having a color spectrum 55 of an opening width b.

11a and 11b illustrate another embodiment of a white light source 1, a collimating unit 4, and an optical unit as the spectrometer unit 2 to form a multi-colored light beam 31. Figure 11a shows a side view and Figure 11b shows a top view of the overall. The white light source 1 includes an LED strip 40 that is equipped with a microlens 41 and a first lens 42. The collimating unit 4 includes a plurality of lenses 43, 44 and 45 to suppress parallax effects, and further includes a aperture member 50 having a variable opening width and a collimating grid 46 for collimating the white light source 1 emits a diffused white light beam. The collimated white light beam 30 is converted from one 稜鏡 2 to one of the multi-colored light beams 31 of the rainbow color.

12a and 12b illustrate another embodiment of a white light source 1, a collimating unit 4, and a spectrometer unit, wherein the white light source 1 includes a curved LED strip including a curved strip-shaped microlens 41. To pre-align the white LED light emitted by the camera. Figure 12a shows a top view and Figure 12b shows one of the overalls Side view. The light of the curved light source 1 enters a collimating unit 4, and is aligned by a first lens 42 (which is a cylindrical lens), and passes through a porous member 50 having an adjustable opening width, and finally leaves the quasi- The straight unit 4 is previously focused by a second lens 43 (which is an elliptical lens). The collimated white light beam 30 is then reflected and converted to a multi-color beam 31 by an optical diffraction grating as spectrometer unit 51. One surface of a test product 5 is configured to be parallel to the optical axis of the collimated white light beam 30 below the optical diffraction grating as the spectrometer unit 51.

13a and 13b illustrate a similar embodiment of a white light source 1, a collimating unit 4, and a spectrometer unit, wherein the spectrometer unit is an optical unit 2. Figure 13a shows a top view and Figure 13b shows a side view of the general. The white light source 1 includes an LED strip 40 that is bent with one of the curved strip-shaped microlenses 41 to pre-align a strip of white light emitted by the LED strip 40, which is collimated by a collimating unit 4. The collimating unit 4 includes a first lens 42 (which is a cylindrical lens), a aperture member 50 having a slit aperture having a variable opening width, and a second lens 43 (which is an elliptical lens). Finally, the collimating unit 4 includes a third lens 44 at its optical end, and the collimated white light beam 30 enters an optical 稜鏡 2 as a spectrometer unit to be diffracted to a multi-color beam 31, which strikes Under test one of the surfaces of product 5.

Figures 14a and 14b show a schematic view of an LED strip 40, such as a light source having an attached collimating unit 4 and a aperture member 50 in the form of an aperture. Figure 14a shows an LED strip 40 comprising a plurality of white LEDs 60. Each LED 60 emits uncollimated white light that is aligned and pre-collimated by a microlens 41. The microlens is attached close to the LED 60. The pre-collimated white light enters a collimating tunnel 64 in which a first lens 42 (which is a cylindrical lens) and a fifth lens 62 are disposed to further collimate the light. The tunnel has a rectangular cross section and has a length such that when white light emitted by the LED 60 enters the aperture member 50 which is a slit aperture, it has a void angle of 3 or less.

Finally, Figures 15a, 15b and 15c schematically illustrate one configuration of an embodiment of measuring a measuring device 15 of a test product 5. The embodiment of the measuring device 15 returns to the configuration of Figure 1a. An LED strip 40 produces a white light beam 30 that is collimated by a collimating unit 4 comprising a plurality of collimating lenses 43a through 43e such that a collimated white light having a collimating angle of one of 3 or less is formed. The spectrometer unit 2, in the form of an optical 扩大, expands the collimated white light beam 30 into a multi-colored light beam 31 comprising one of the components of the color spectrum starting point 7 and one of the color spectrum one end 8 . In Figure 1, the waterfall of the multi-color beam is directed towards a test product 5. In contrast, in FIGS. 15a to 15c, an achromatic lens unit 66 is disposed between the optical 稜鏡 2 as the spectrometer unit 2 and the test product 5 under test. In Fig. 15a, an achromatic lens unit 66 includes a convex mirror 68 for reflecting a multi-color beam 31 onto the device 5 under test. The width of the spectrum of the multi-color beam 31 and hence the accuracy of the height measurement depends to a large extent on the form of the surface topography of the convex mirror 68 and the distance between the convex mirror 68 and the optical pupil as the spectrometer unit 2 and the test product 5. And can be adjustable. In Fig. 15b, the achromatic lens unit 66 includes two continuously arranged convex mirrors 68 to focus the multi-color beam 31, thereby reducing the spectral width and resulting in an increase in height resolution. Figure 15c of the achromatic lens Element 66 includes a combination of a convex mirror 68 and a focusing lens 70 to increase the intensity of the spectral light. The achromatic lens unit 66 can focus the spectral light to a small height so that the height resolution can be generated, whereby the focus property of the achromatic lens unit 66 can be adjusted depending on a desired resolution, for example, By changing the convex mirror 68 or the focusing lens 70 to the optical 作为 as the spectrometer unit 2 and/or the distance to the test product 5. The achromatic lens unit 66 can include a plurality of mirrors 68 and lenses 70, and can also include one or more telemetry lenses, advantageously a barrel or columnar lens. A telecentric lens is a compound lens having an infinite entrance or exit pupil; in the former case, this produces an orthographic view of the subject. This means that the main light (the oblique light passing through the center of the aperture stop) is parallel to the optical axis in front of or behind the system, respectively.

Another embodiment of the device can be used to test a circuit board containing electronic components:

The measuring device 15 is calibrated such that a zero height is defined on the surface of the mounting (master) board 5 such that after scanning, the board (ground) will be displayed in a darker red (starting 7 of the spectrum). The measurement range is selected based on the purple component 12 of the white light spectrum (the highest measurement portion of the test product 5).

In the test equipment, this position is defined along with the height and tolerance of the test product 5 (the board).

经过 After passing the board through the line scan camera 3, its individual components are displayed in color depending on their height.

传输Use the software of the calibration function to transfer the chromaticity to the height given in millimeters value.

评估 In the area of the test, the actual height of the component is evaluated, and the output is in the form of information relative to the specified tolerance, the information indicating the test product 5, whether the board as a whole (or its individual components) has defect.

Another embodiment of the device can be used to test the surface of a board or the surface of a solar cell product:

The measuring device 15 is calibrated such that the surface in a normally acceptable state will be displayed after scanning a color (green) that is generally approximately centered in the spectrum.

̇ Select the measurement range, that is, the maximum (maximum) and minimum (minimum) deviations that can occur on the test board (the curvature of the board, surface defects, cracks, wear, deposits, etc.). This minimum deviation will be displayed in red and the maximum deviation will be purple.

The entire surface of the calibration body can be defined as a test area, and the tolerance of the deviation is selected.

The board can be scanned by means of a line scan camera 3.

Using this calibration function, the software converts the chromaticity to a height value given in millimeters or micrometers.

̇ Evaluate if any areas have a larger deviation than the allowable tolerance. The output can be information indicating whether the product 5 (board) tested is defective.

Industrial applicability

The technical solution of the invention can be used in particular for individual products or groups thereof The geometry of the distance of the part and the approximation or target inspection of the measurement, especially in the distance between the part where the optical measurement sensor and the test are necessary, that is, in the direction in which the change is not reflected in the image in the normal state.

1‧‧‧White light source

2‧‧‧Spectrometer unit

3‧‧‧ camera

4‧‧‧ Collimation unit

5‧‧‧Test products (eg PCB)

6‧‧‧The width of the color spectrum

7‧‧‧The beginning of the color spectrum

8‧‧‧End of the color spectrum

9‧‧‧Scanning direction

10‧‧‧ has a composition corresponding to the height of one of the white light spectra - red component

11‧‧‧Having a component corresponding to the height of one of the white light spectrums - green component

12‧‧‧ has a composition corresponding to the height of purple of the white light spectrum - purple component

15‧‧‧Measurement device

16‧‧‧Electronic components

17‧‧‧Pore width of the collimating unit

18‧‧‧ Opening angle α

19‧‧‧ Calibration body

20‧‧‧Calibration angle β

21‧‧‧Control unit

22‧‧‧Control components

23‧‧‧Hue height mapping component

24‧‧‧ Camera aperture unit

30‧‧‧ Collimated white beam

31‧‧‧Multi-color beam

32‧‧‧Reflected single color beam

40‧‧‧Lighting diode strip (or LED strip)

41‧‧‧Microlens

42‧‧‧First lens

43‧‧‧second lens

44‧‧‧ third lens

45‧‧‧Fourth lens

46‧‧‧ collimation grid

50‧‧‧Pore components

51‧‧‧ Optical diffraction grating as spectrometer unit

55‧‧‧Color spectrum

60‧‧‧Lighting diode

62‧‧‧ fifth lens

64‧‧ ‧ Collimation tunnel

66‧‧‧Achromatic lens unit

68‧‧‧ convex mirror

70‧‧‧focus lens

1a and 1b illustrate a first embodiment of a measuring device of the present invention for inspecting an electronic component alignment on a PCB; and FIG. 2 illustrates the first implementation of a measuring device in accordance with the present invention. For example, it is used to inspect a thin electronic component on a PCB corresponding to a red spectrum; FIG. 3 illustrates the first embodiment of a measuring device according to the present invention for inspecting a PCB corresponding to a green spectrum 1 is a medium-sized electronic component; FIG. 4 illustrates the first embodiment of a measuring device according to the present invention for inspecting a larger electronic component on a PCB corresponding to a purple spectrum; FIG. An example of a color spectral tone height map having a scale range of 0 mm to 10 mm; Figures 6a, 6b illustrate another embodiment of a measuring device according to the present invention having an adjustable aperture Figure 7a, Figure 7b illustrates another embodiment of a measuring device according to the present invention having an adjustable optical bore; Figures 8a, 8b illustrate another embodiment of a measuring device in accordance with the present invention , having an adjustable height optical 稜鏡; 9 illustrates another embodiment of the present invention, one of the measuring device; FIG. 10a, FIG. 10b illustrates one configuration of a light source and collimating means in accordance with one embodiment of the present invention, one of the measurement device; 11a and 11b illustrate another light source and collimating unit configuration of an embodiment of a measuring device according to the present invention; and FIGS. 12a and 12b illustrate another embodiment of one of the measuring devices according to the present invention. Light source and collimation unit configuration; Figures 13a, 13b illustrate another light source and collimation unit configuration of one embodiment of a measurement device in accordance with the present invention; Figures 14a, 14b depict one measurement in accordance with the present invention Another light source and collimating unit configuration of one embodiment of the device; and FIGS. 15a, 15b, and 15c illustrate another light source and a quasi-sequence unit having an embodiment of one of the measuring devices according to the present invention Straight unit.

1‧‧‧White light source

2‧‧‧Spectrometer unit

3‧‧‧ camera

4‧‧‧ Collimation unit

5‧‧‧Test products (eg PCB)

6‧‧‧The width of the color spectrum d

7‧‧‧The beginning of the color spectrum

8‧‧‧End of the color spectrum

9‧‧‧Scanning direction

10‧‧‧ has a composition corresponding to the height of one of the white light spectra - red component

11‧‧‧Having a component corresponding to the height of one of the white light spectrums - green component

12‧‧‧ has a composition corresponding to the height of purple of the white light spectrum - purple component

15‧‧‧Measurement device

16‧‧‧Electronic components

30‧‧‧ Collimated white beam

31‧‧‧Multi-color beam

32‧‧‧Reflected single color beam

55‧‧‧Color spectrum

Claims (15)

A device (15) for optically measuring the surface of a test product (5), in particular for the surface of a PCB product for reflow solder paste inspection, comprising at least one white light source (1) for emission a white light beam, at least one collimating unit (4) for collimating the collimated white light beam (30), at least one spectrometer unit (2, 51), preferably an optical or optical Diffusing the grating to split the collimated white beam (30) into a multi-color beam (31) that is directed onto the test product (5) below a predetermined angle of incidence γ, and at least one camera (3) ) for recording a single color beam (32) reflected by one of the test products (5), the device being configured such that one of the z-axis surface height information of the test product (5) is in an x-axis scan direction (9) relatively moving the test product (5) from a tone value of one of the reflected single color beams (32), characterized in that the white light source (1) is an LED strip (40) that is adapted To generate a white light strip beam, wherein at least one microlens (41) is optically coupled to at least one LED to pre-align the white light beam, and the collimating unit (4) is adapted to Collimating the white light beam (30) with a collimating quality of 2° or less in the 360° direction, and forming a white light strip beam perpendicular to the scanning direction (9), and including at least one lens (42, 43) 44, 45), which is preferably a cylindrical lens, and at least one aperture member (50), which is preferably an adjustable slit aperture. The device of claim 1, wherein the white light source (1) has a continuous color spectrum (55), and/or the frequency spectrum of the color spectrum (55) is variable, Preferably, the intensity of the white light source (1) is adjustable, preferably by dimming the light source (1), or by selectively Two or more light sources (1) are turned on or off in parallel. A device according to claim 1 or 2, wherein the plurality of LEDs of one of the LED strips (40) are selectively switchable to be turned on or off to enhance the collimated white beam in a y-axis direction perpendicular to the scanning direction (9) (30) Strength and / or length. The device of claim 1 or 2, further comprising a scan transmission member for relatively transmitting the test product (5) or the light source (1), a spectrometer unit, a quasi in a scanning direction (9) Straight unit (4) and a camera (3). The device of claim 1 or 2, wherein the camera (3) is a line scan camera, preferably comprising a camera aperture unit (24) and/or a parallax lens unit to reduce parallax effects, especially a columnar shape a lens or circular lens unit for receiving a single color beam (32) reflected by the test product (5) from one of the multi-color beams (31), and/or the camera (3) having at least 8 bits a tonal resolution digital camera, preferably an adjustable 10-bit, 12-bit or higher tonal resolution, and/or the camera (3) includes two or more line scan columns, Each column includes a color filter for increasing hue sensitivity, and/or the camera (3) includes at least one gray or black/white scan column to enhance scanning quality, or the camera (3) is a side scan A camera in which a single or multiple scan columns of the scan area can be extracted for tone height information processing. A device according to claim 1 or 2, comprising at least two or more cameras (3) arranged in a y-axis direction perpendicular to the x-scan direction (9) for parallel scanning, thus enhancing the Test product (5) scan width and / Or the cameras (3) are stereoscopically configured to scan the test product (5) in 3D to reduce shadowing and illumination effects. A device according to claim 1 or 2, further comprising a control unit (21) electrically coupled to at least the camera (3), the control unit (21) comprising a control member (22) and a tone height mapping member (23), It is adapted to at least control the camera (3) and map the tonal value of one of the images captured by the camera (3) to a surface height information of the test product (5). The device of claim 7, further comprising an adjustment member controllable by the control member (22) of the control unit (21) to adjust a color spectral width d(6) of the multi-color beam (31), particularly Adjusting the armature width w (17) of one of the collimating units (4), and/or for adjusting a beam splitting height b, the distance a between the source (1) and the camera (3) or the splitting The angle α of the unit is measured to adjust the height measurement sensitivity. A method for optically measuring the surface of a test product (5), in particular for use in a reflow solder paste inspection of a PCB product using a device according to any of the preceding claims, wherein a collimated white beam Emitted by the white light source (1), and aligned and collimated by the collimating unit (4) into a parallel narrower beam (30) passing through the spectrometer unit (2, 51), the beam being split by the spectrometer The unit is decomposed into a color spectrum (55), which is recorded by the camera (3) when the test product (5) is moved relative to the camera (3) in a scanning direction (9) in the test product (5) Or reflection on its components such that one of the images from the individual images of the camera (3) displays all portions of the surface of the test product (5), and the image corresponds to the dimensions in the x-axis and y-axis directions For the test production The actual size of the product (5), and at the same time, the tonal value of the image, i.e., the value of the color portion [R, G, B] of the individual pixel, is assigned to the surface height value of the test product (5). The method of claim 9, wherein the hue value of the color spectrum (55) is mapped to a hue height of the z surface height value to have a high accuracy of a known one of the calibration angles β (20) by a calibration body (19) At least one of the surface undercuts is calibrated and calibrated, and a tone height map is stored in the one-tone height mapping member (23). The method of claim 9 or 10, wherein the geometric position of the camera (3) and the light source (1) is stationary during the entire scanning time, and/or an instant tone height map is used during the scanning period. carried out. The method of claim 9 or 10, wherein the camera (3) progressively records the tone value of the surface of one of the test products (5) progressively while facing the test product (5) in a scan direction (9). Move the camera (3). The method of claim 9 or 10, wherein the camera (3) and the white light source (1) are adjusted such that the start (7) of the color spectrum (55) is mapped to zero height and/or by the camera (3) The recorded tone values are converted to the actual surface height of one of the test products (5) or components thereof by means of a calibration function, preferably by a tone height map. The method of claim 9 or 10, wherein the 3D model of the test product (5) is established based on the measured x and y values of one of the images of the camera (3), and a z-height value is based on the image The tone values on the x-axis and y-axis are established. The method of claim 9 or 10, wherein the size of one of the test products (5), in particular, the position and height of the reflow solder paste on a PCB or solar cell product, and/or the surface roughness of the test product (5) Degree, measured.