Measuring device and method for circuit board

Abstract

According to the circuit board measuring device and method provided by the invention, the polychromatic light is generated through the polychromatic light source, the polychromatic light is divided into the light beams comprising the plurality of different wavebands through the spectroscope, and the light beams comprising the plurality of different wavebands are focused through the optical lens module and are accurately incident to the surface of the target position of the back drilling hole to be reflected to form the reflected light. The reflected light is subjected to light splitting through the light splitter, polychromatic light is decomposed into monochromatic light with different wavelengths, so that the spectrograph accurately measures and analyzes the light intensity of each wavelength, and the spectrograph calculates target parameters of the back drilling hole based on the reflected light subjected to light splitting. And non-contact and high-precision measurement of target parameters (such as the length of a residual column and the drilling depth of a back drilling hole) is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of circuit board measurement, and in particular relates to a circuit board measurement device and method. Background Art

[0002] During the printed circuit board (PCB) manufacturing process, back-drilled hole parameters (such as drill depth and residual pile length) need to be measured. Related technologies use X-ray imaging or fiber optic penetration for detection. However, X-ray imaging has insufficient resolution at small apertures, which can easily lead to image blur and missed detections. Fiber optic penetration detection is prone to damage to the optical fiber, resulting in increased detection costs and reduced efficiency. In other words, existing methods suffer from slow detection speed and low accuracy. Summary of the Invention

[0003] In view of this, embodiments of the present application provide a circuit board measurement device and method, which can achieve non-contact, high-precision measurement of target parameters of back drilling.

[0004] In a first aspect, an embodiment of the present application provides a measuring device for a circuit board, wherein the circuit board has a back-drilled hole, and the measuring device for the circuit board includes: a polychromatic light source configured to emit polychromatic light; an optical lens module configured to receive the polychromatic light, split the polychromatic light into light beams comprising a plurality of different wavelength bands, focus the light beams comprising the plurality of different wavelength bands, and then project them into the back-drilled hole along a first optical path so as to be reflected from a surface at a target position of the back-drilled hole to form reflected light, and to receive and focus reflected light formed by reflection of light beams of at least one wavelength band, and then project the reflected light along a second optical path; a spectrometer, disposed in the second optical path, for splitting the reflected light; A spectrometer is used to determine target parameters of the back-drilled hole according to spectral information of the reflected light after spectroscopy.

[0005] In some embodiments, the optical lens module includes a beam splitter and a focusing lens; The beam splitter is used to split the polychromatic light into the light beams comprising the plurality of different wavelength bands, and adjust the propagation directions of the light beams comprising the plurality of different wavelength bands along the propagation direction of the first optical path, wherein the propagation direction of the first optical path is perpendicular to the axis of the back-drilled hole, and to allow the light beams comprising the plurality of different wavelength bands to be incident on the focusing mirror, and is further used to receive reflected light formed by reflection of the light beam of at least one wavelength band and emit the reflected light along the second optical path; The focusing mirror is used to focus the light beam of the at least one wavelength band and inject the focused light beam of the at least one wavelength band into the back-drilled hole, and is also used to receive and focus the reflected light formed after the light beam of the at least one wavelength band is reflected and then emit it to the spectroscope.

[0006] In some embodiments, the polychromatic light source comprises: a light source for generating monochromatic laser light of a preset wavelength; The atomic luminescent phosphor is used to emit light under the irradiation of the monochromatic laser to generate complex light, wherein the light intensity difference between any two lights in the complex light is less than a preset threshold.

[0007] In some embodiments, the optical lens module further includes: The shaping module is arranged between the beam splitter and the focusing mirror and is used to adjust the optical path of the light beam.

[0008] In some embodiments, the beam splitter and the focusing lens are liquid lenses, and the refractive index of the liquid lens can be changed by changing the voltage applied to the liquid lens.

[0009] In some embodiments, the measuring device for the circuit board further includes: a first driving component, which is connected to the spectrometer and / or focusing mirror and is used to drive the spectrometer and / or focusing mirror to move to change the distance between the spectrometer and the focusing mirror.

[0010] In some embodiments, the measuring device further includes: a second drive assembly, which is used to connect to the optical lens module and drive the optical lens module to move in a direction parallel to the surface of the circuit board to determine the target parameters of multiple detection positions.

[0011] In some embodiments, the circuit board measuring device further includes: a moving platform, the moving platform is used to place the circuit board, and the moving platform is used to drive the circuit board to move to determine target parameters of multiple detection positions.

[0012] In some embodiments, the measuring device further includes a filter device, which is disposed in the optical path between the optical lens module and the spectrometer. The filter device is provided with filter micropores, which are used to filter out stray light of non-focus wavelengths.

[0013] In a second aspect, an embodiment of the present application provides a method for measuring a circuit board, wherein the circuit board has a backdrilled hole, and the circuit board has a dielectric layer and a signal layer. The method is applied to the circuit board measuring device according to any one of the first aspects, comprising: controlling a polychromatic light source to generate polychromatic light, so as to form a polychromatic light beam in the back-drilled hole, wherein the polychromatic light beam includes light beams of multiple different wavelength bands; Reflected light formed by reflection of a light beam of at least one wavelength band is received, and target parameters of a back-drilled hole in the circuit board are determined according to spectral information of the reflected light.

[0014] In some embodiments, the target parameter includes a drilling depth of the backdrilled hole; The receiving of reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of the back drilling hole in the circuit board according to spectral information of the reflected light, includes: receiving a first reflected light formed by reflection of a light beam of a wavelength band in the polychromatic light beam; The drilling depth of the back-drilled hole is determined according to the spectral information of the first reflected light.

[0015] In some embodiments, the target parameter includes the stump length of the back-drilled hole; The receiving of reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of the back drilling hole in the circuit board according to spectral information of the reflected light, includes: receiving a second reflected light formed by reflection of the light beams of two wavelength bands in the polychromatic light beam; The length of the stump of the back-drilled hole is determined according to the spectral information of the second reflected light.

[0016] In some embodiments, the circuit board includes: a dielectric layer and a signal layer; the second reflected light includes: a first sub-reflected light and a second sub-reflected light; the first sub-reflected light is reflected light from the dielectric layer in the back-drilled hole; the second sub-reflected light is reflected light from the signal layer in the back-drilled hole; and determining the stump length of the back-drilled hole based on spectral information of the second reflected light includes: calculating an optical path difference based on spectral information of the first sub-reflected light and spectral information of the second sub-reflected light; The stump length of the back-drilled hole is calculated based on the optical path difference.

[0017] In some embodiments, receiving reflected light formed after reflection of a light beam in at least one wavelength band, and determining target parameters of the backdrilling hole in the circuit board based on spectral information of the reflected light, includes: A plurality of detection positions are arranged at intervals in the back-drilled hole along the horizontal direction of the circuit board; Controlling the optical lens module and the circuit board to move relative to each other along the surface of the circuit board to obtain reflected light from a plurality of detection positions; Obtaining corresponding detection parameters of a plurality of back-drilled holes according to the plurality of reflected lights; Target parameters for back drilling in the circuit board are determined based on the detection parameters.

[0018] In some embodiments, determining target parameters for backdrilling in the circuit board based on the detection parameters includes: removing abnormal values ​​from the detection parameters corresponding to the plurality of detection positions to obtain screening detection parameters, wherein a deviation between the abnormal value and the other detection parameters is greater than a deviation threshold; Target parameters of the backdrilling hole are determined based on the screening detection parameters.

[0019] In some embodiments, the spectrometer and focusing lens in the optical lens module of the circuit board measuring device are liquid lenses, the circuit board measuring device further includes: a first driving assembly, and the method further includes: Obtaining a diameter of the back-drilled hole and a back-drilled hole depth ratio; Determining target voltages applied to the beam splitter and the focusing mirror based on the ratio of the diameter to the back-drilled hole depth, and determining focal lengths of the beam splitter and the focusing mirror and their mutual distances in the optical system; The target voltage is applied to the beam splitter and the focusing mirror, and the first driving component is controlled to adjust the distance between the focal lengths of the beam splitter and the focusing mirror in the optical system to the mutual distance. When the target voltage is applied to the beam splitter and the focusing mirror, and the distance between the focal lengths of the beam splitter and the focusing mirror in the optical system is the mutual distance, the light beam focused by the focusing mirror can be incident into the back-drilled hole, and the focus can adapt to different drilling depth measurements of the back-drilled hole.

[0020] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above-described methods when executing the computer program.

[0021] In a fourth aspect, an embodiment of the present application provides a spectrometer, comprising the electronic device in the third aspect.

[0022] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements any of the methods described above.

[0023] In a sixth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the electronic device to execute any of the methods described above.

[0024] Compared with the prior art, the embodiments of the present application have the following beneficial effects: An embodiment of the present application provides a circuit board measuring device, which generates polychromatic light through a polychromatic light source, divides the polychromatic light into light beams including multiple different bands through a spectroscope, focuses the light beams including multiple different bands through an optical lens module and accurately incidents on the surface of the target position of the back-drilled hole for reflection to form reflected light, splits the reflected light through a spectrometer to decompose the polychromatic light into monochromatic light of different wavelengths, so that a spectrometer can accurately measure and analyze the light intensity of each wavelength. The spectrometer calculates the target parameters of the back-drilled hole based on the split reflected light, thereby realizing non-contact, high-precision measurement of the target parameters (such as residual column length and back-drilled hole drilling depth). BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A test schematic diagram of a circuit board measuring device provided in an embodiment of the present application; Figure 2 A schematic diagram of a detection principle provided in an embodiment of the present application; Figure 3 A schematic diagram of the reflection of light of a specific wavelength in a dielectric layer and a signal layer provided in an embodiment of the present application; Figure 4 Schematic diagram of wavelength and light intensity of a traditional composite light source; Figure 5 A schematic diagram of wavelength and light intensity provided in an embodiment of the present application; Figure 6 A comparison chart showing the light received by a white LED light source provided in the related art and the light received by a polychromatic light source provided in an embodiment of the present application; Figure 7 A schematic structural diagram of an optical lens module provided in an embodiment of the present application; Figure 8 A schematic diagram of a circuit board measurement method according to an embodiment of the present invention; Figure 9 A schematic diagram of determining the drilling depth of multiple detection positions in a back-drilled hole provided in an embodiment of the present application; Figure 10 A schematic diagram of measuring target drilling depths of multiple back-drilled holes provided in an embodiment of the present application; Figure 11 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application; Figure 12 A schematic structural diagram of a back-drilling measurement system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0028] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0029] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0030] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if it is detected" can be interpreted as meaning "upon determining" or "in response to determining" or "upon detecting" or "in response to detecting," depending on the context.

[0031] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0032] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized.

[0033] Based on the problems in the related art, the embodiment of the present application provides a measuring device for a circuit board. Figure 1A test diagram of a circuit board measuring device provided in an embodiment of the present application is shown as follows: Figure 1 As shown, the circuit board 200 has back-drilled holes therein, and the circuit board has a dielectric layer 201 and a signal layer 202 .

[0034] In the embodiments of this application, backdrilling is a secondary drilling process in multilayer PCB manufacturing to remove unused copper sections from vias, thereby shortening the stub length. Dielectric layers are insulating layers used to isolate adjacent signal layers in a PCB. Common materials include FR4 (glass fiber reinforced epoxy) and Rogers (low-loss high-frequency materials) M8 and M9. Signal layers are the copper foil layers that transmit electrical signals in a PCB and are typically arranged alternately with power / ground layers.

[0035] Continue to see Figure 1 The circuit board measuring device includes: a polychromatic light source 101, an optical lens module, a spectrometer 103 and a spectrometer 104. The polychromatic light source 101 is used to emit polychromatic light. The optical lens module is configured to receive the polychromatic light, split the polychromatic light into light beams including multiple different wavelength bands, focus the light beams including multiple different wavelength bands and then incident on the back-drilled hole along a first optical path to reflect on the surface of the target position of the back-drilled hole to form reflected light, and receive and focus the light beams of at least one wavelength band after reflection, and then emit the reflected light along a second optical path. The spectrometer 104 is arranged in the second optical path and is used to split the reflected light. The spectrometer 104 is used to determine the target parameters of the back-drilled hole based on the spectral information of the split reflected light.

[0036] In the embodiments of the present application, the polychromatic light source provides polychromatic light with multiple wavelengths, covering the wavelength range detectable by the spectrometer (typically 400-1200 nm). Compared to monochromatic light, polychromatic light can simultaneously stimulate the reflected signal of the surface at the target location, improving detection efficiency.

[0037] In an embodiment of the present application, the target position may include: a dielectric layer and a signal layer. In some embodiments, the target position may be the bottom of a back-drilled hole, and the target parameters may include: the length of the residual pile or the drilling depth of the back-drilled hole.

[0038] In the embodiment of the present application, when the target location includes both the dielectric layer and the signal layer, two beams of reflected light are reflected. The optical path difference can be obtained from the spectral information of the two beams of reflected light, and the residual column length of the backdrilled hole can be obtained from the optical path difference. When the target location is the bottom of the backdrilled hole, a single beam of reflected light is reflected, and the spectral information of the reflected light can be used to determine the drilling depth of the backdrilled hole.

[0039] In the embodiment of the present application, the optical lens model may include a beam splitter, a focusing lens and a shaping module.

[0040] In the embodiment of the present application, the spectroscope 105 uses a plane grating to decompose the reflected light into a wavelength-intensity distribution curve. The spectrometer is equipped with a CMOS linear array sensor to collect the spectrum, and the target parameters are calculated by the spectrometer. The spectrometer has a wavelength resolution of up to 0.15nm, which is sufficient to distinguish target parameters at the un-level. The signal-to-noise ratio is greater than 20,000:1, and it has extremely strong sensitivity, strong resistance to external light interference, and strong ability to measure the target signal layer that light penetrates, with high precision.

[0041] An embodiment of the present application provides a circuit board measuring device, which generates polychromatic light through a polychromatic light source, divides the polychromatic light into light beams including multiple different wavelengths through a spectroscope, focuses the light beams through an optical lens module and accurately incidents on the surface of a target position of a back-drilled hole for reflection to form reflected light, splits the reflected light through a spectrometer to decompose the polychromatic light into monochromatic light of different wavelengths, so that a spectrometer can accurately measure and analyze the light intensity of each wavelength. The spectrometer calculates the target parameters of the back-drilled hole based on the split reflected light, thereby realizing non-contact, high-precision measurement of the target parameters (such as residual column length and back-drilled hole drilling depth).

[0042] In some embodiments, see Figure 1 The optical lens module includes a beam splitter 105 and a focusing mirror 106; the beam splitter 105 is used to split the polychromatic light into light beams including multiple different bands, and adjust the propagation direction of the light beams including multiple different bands along the propagation direction of the first optical path. The propagation direction of the first optical path is parallel to the axis of the back-drilled hole, and the light beams including multiple different bands are incident on the focusing mirror 106, and are also used to receive the reflected light formed after the light beam of at least one band is reflected and then emit it along the second optical path; the focusing mirror 106 is used to focus the light beams including multiple different bands, and the focused light beams are incident on the back-drilled hole, and are also used to receive and focus the reflected light and then emit it to the beam splitter 105.

[0043] In this embodiment of the present application, the beam splitter 105 is used to decompose the polychromatic light into multiple beams of different wavelength bands by wavelength (e.g., using a prism or grating) and align the beams to be parallel to the axis of the back-drilled hole. The beam splitter can be a 45° beam splitter. The focusing lens 106 focuses the split beams into a narrow beam of at least one wavelength band to improve spatial resolution. The focal depth can be optimized based on the back-drilled hole diameter and the inspection drilling depth (typically <2 mm) to avoid beam divergence. The focusing lens is also used to collect scattered light reflected from the back-drilled hole and collimate it into parallel light for subsequent spectroscopic processing.

[0044] In the embodiments of the present application, when using a circuit board measurement device, the angles of the polychromatic light source and the beam splitter can be adjusted to ensure that the light beam is parallel to the axis of the back-drilled hole. The position of the focusing lens can also be adjusted to adjust the focal length so that the light beam is focused on the target location (dielectric layer interface) in the back-drilled hole. The focal length here can also be referred to as the focal depth. The focal depth range can be set based on the properties of the focusing lens. Measurements can be performed within a focal depth range. For example, the focal depth range can be less than 1.4 mm.

[0045] Within the preset focal depth range, Figure 2 A schematic diagram of a detection principle provided in an embodiment of the present application is shown as follows: Figure 2 As shown, when the optical lens module projects light, multiple light beams of different wavelengths have different focal lengths. Figure 2 Multiple light beams of different wavelengths are focused at different positions. Usually, red light has the smallest focal length and blue light has the largest focal length. Each specific distance (the distance from the focusing lens to the dielectric layer step of the back-drilled hole and the distance from the focusing lens to the signal layer in the back-drilled hole) corresponds to a specific wavelength. Within this focal depth range, there is always a specific wavelength that can be focused on the dielectric layer, and there is always a specific wavelength of light that can be focused on the signal layer. Figure 3 A schematic diagram of the reflection of light of a specific wavelength in a dielectric layer and a signal layer provided in an embodiment of the present application is shown as follows: Figure 3 As shown, the light beam reflects off the dielectric layer to produce reflected light, while the light beam reflects off the surface of the signal layer to produce reflected light. The two reflected light beams can be used to calculate the length of the stump. In the embodiment of the present application, the spectrometer in the optical lens module is both a component of the coaxial confocal optical path and a core component of the dispersive optical path. When measuring the stump length, after the polychromatic light passes through the spectrometer, the spectrum is evenly distributed along the Z-axis. After being focused by the focusing mirror, the light is first reflected at the interface between the dielectric layer and air at the stepped position of the back-drilled hole, forming a first sub-reflected light. A second reflection occurs at the interface between the dielectric layer and the signal layer, forming a second sub-reflected light. The two reflected lights have different wavelengths and belong to different specific wavelengths. The two reflected light beams are successively converged by the focusing mirror. The spectrometer refracts the light, and the spectrum detector detects which two wavelengths of light are reflected first and last. Based on the distribution distance of the color bands, the optical path difference between the two light beams can be directly obtained, thus obtaining the length of the stump in the back-drilled hole. When measuring the back-drilling depth, after the polychromatic light passes through the spectrometer, the spectrum is evenly distributed along the Z-axis. After being focused by the focusing mirror, it is reflected at the bottom of the back-drilled hole. The reflected light is converged by the focusing mirror, refracted by the spectrometer, and finally sensed by the spectrum detector, so that the drilling depth of the back-drilled hole can be calculated based on the reflected light.

[0046] The complex color light source provided in the related art uses an ordinary white LED light source. Figure 4 Schematic diagram of wavelength and light intensity of traditional composite light source, such as Figure 4As shown, the horizontal axis is wavelength and the vertical axis is light intensity. The wavelength range of the polychromatic light source is short, the light intensity distribution is uneven, and the wavelength band of high-brightness light emission is relatively narrow, which will result in a small amount of light in the range segment. For example, after passing through the chromatic aberration optical lens group, the white light is divided into red, yellow, blue and other colors. It can be seen that the yellow light in the middle part has a large amount of light, while the yellow and blue light at the edge of the polychromatic light have a small amount of light, resulting in a low detected signal intensity and low detection accuracy. In order to improve the detection accuracy, the polychromatic light source includes: a light source for generating a monochromatic laser of a preset wavelength; an atomic luminescent phosphor for emitting light under the irradiation of the monochromatic laser to generate polychromatic light, wherein the light intensity difference between any two lights in the polychromatic light is less than a preset threshold.

[0047] In the embodiments of the present application, the monochromatic laser can be a blue laser. The blue laser light source serves as the excitation source, providing high-energy-density monochromatic light (typically with a wavelength of 445-465 nm). Blue laser light sources have the following characteristics: narrow linewidth, high power, and stability. Typically, the linewidth is less than 1 nm to ensure efficient excitation. The output power of the blue laser light source can reach 100 mW to 1 W, meeting the requirements for phosphor excitation. The power fluctuation of the blue laser light source is less than ±1%, preventing variations in light intensity from affecting the uniformity of the polychromatic light.

[0048] In the embodiments of the present application, an atomic luminescent phosphor, under blue laser excitation, generates a broad spectrum of polychromatic light through electron transitions. The atomic luminescent phosphor can be such that blue laser photons are absorbed by the phosphor, causing electrons to transition from a ground state to an excited state. The excited electrons relax to a metastable state through a non-radiative transition (such as a Stokes shift), then radiatively transition back to the ground state, emitting low-energy photons (long-wavelength light). This generates polychromatic light including blue, green, yellow, orange, and red.

[0049] In this embodiment, the ratios of the various phosphors can be adjusted to ensure that the intensities of blue (excitation light residue), green, yellow, orange, and red light in the composite light are close. Spectral simulation can be used to calculate the composite spectrum of the composite light by inputting the phosphor emission spectra and concentrations. The preset threshold can be configured, illustratively, to ensure that the difference between the intensities of any two colors is less than 10% (relative intensity). For example, if the blue light intensity is 100mW, the intensities of the other colors must be between 90-110mW.

[0050] In the embodiment of the present application, a diffusion plate (such as frosted glass) can be placed in front of the phosphor to allow the blue laser to evenly illuminate the surface of the phosphor.

[0051] Figure 5 A schematic diagram of wavelength and light intensity provided in an embodiment of the present application is shown in FIG. Figure 5As shown, a blue laser is irradiated on an atomically luminescent phosphor that emits both red and green light, generating a broad, high-intensity, polychromatic light. Compared to conventional white LED light sources, this achieves stable, high-brightness light across a wider wavelength range. Figure 6 This is a comparison chart of the light received by the white LED light source provided in the related art and the light received by the polychromatic light source provided in the embodiment of the present application, as shown in FIG. Figure 6 As shown, the white LED light source in the related art receives less light, while the polychromatic light source of this proposal can obtain sufficient light reception at different positions.

[0052] The circuit board detection device provided in the embodiments of this application features different reflection characteristics of light of different wavelengths in the dielectric layer and signal layer. This allows a single detection to capture multiple drilling depths, improving detection efficiency by 3-5 times compared to traditional monochromatic light. A balanced light intensity design ensures similar reflected signal intensities for each light color (e.g., all >80mW), improving the signal-to-noise ratio of the detected spectral information. This balanced light intensity design prevents signal loss due to excessive scattering of a particular light color, ensuring robust detection. Its multi-wavelength collaborative detection capability significantly improves efficiency and accuracy, while the balanced light intensity design enhances interference resistance.

[0053] In some embodiments, the optical lens module further includes: The shaping module is set between the beam splitter and the focusing mirror to adjust the optical path of the light beam.

[0054] In the embodiments of this application, the beam output from the beam splitter often exhibits the following issues: A large divergence angle causes the beam spot in front of the focusing lens to extend beyond the effective aperture, resulting in energy loss. Furthermore, there is uneven light intensity distribution: the intensity at the center is 2-3 times that at the edges (Gaussian distribution), affecting the consistency of the detection signal. An inclined beam splitter installation can introduce astigmatism, causing the beam's focus position to shift in the X / Y directions.

[0055] In this embodiment of the present application, the divergence angle can be compressed by the shaping module to ensure that the light spot completely enters the effective aperture of the focusing lens. The light intensity distribution is converted from Gaussian to top-hat, so that the edge light intensity is ≥ 80% of the center light intensity.

[0056] The plastic surgery module can include multiple sets of lenses. Figure 7 A schematic diagram of the structure of an optical lens module provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, a shaping module 107 is located between the focusing lens 106 and the beam splitter. This shaping module 107 is composed of multiple lens groups (typically lens arrays). These lenses are the core component of the optical lens module. By combining lenses of different shapes and curvatures, they achieve operations such as refraction and focusing of light. For example, a convex lens can converge light, while a concave lens can diverge it. Through appropriate combinations, a beam can be shaped.

[0057] The circuit board measuring device provided in the embodiment of the present application accurately controls and processes light by setting a shaping module and through the coordinated action of multiple lenses.

[0058] In some embodiments, the beam splitter and the focusing lens are liquid lenses, and the refractive index of the liquid lens can be changed by changing the voltage applied to the liquid lens.

[0059] In the embodiment of the present application, the liquid lens as a spectroscope has the main function of decomposing the polychromatic light into a plurality of light beams of different wavelengths and adjusting the propagation direction of the light beam to be parallel to the axis of the back-drilled hole. By changing the refractive index, the propagation direction and the splitting angle of the light can be precisely controlled to ensure that the light beams of multiple wavelengths can accurately propagate along the predetermined path. The liquid lens as a focusing lens is responsible for focusing the split light beam and directing the focused light beam into the back-drilled hole. Changing its refractive index can adjust the size and position of the focused light spot, so that the light can be accurately focused on a specific position of the back-drilled hole, thereby improving the efficiency of light energy utilization and the accuracy of detection.

[0060] In the embodiments of this application, back-drilled holes of varying sizes require different optical parameters to ensure accurate light entry and reflection detection. The liquid lens adjusts its refractive index via voltage, enabling rapid adaptation to back-drilled holes of varying diameters and depths without the need for physical lens replacement, simplifying the detection process. Precisely controlling the refractive index optimizes light focus and propagation paths, reducing light loss and errors during propagation. This improves the quality of the reflected light signal and detection accuracy, enabling more accurate determination of the target parameters of the back-drilled hole.

[0061] In some embodiments, the circuit board measuring device further includes: a first driving component connected to the spectrometer and / or focusing mirror, and configured to drive the spectrometer and / or focusing mirror to move so as to change the distance between the spectrometer and the focusing mirror.

[0062] In embodiments of the present application, the first drive assembly typically consists of a drive motor, a transmission mechanism (such as a screw-nut mechanism, a rack-and-pinion mechanism, etc.), and a control system. The drive motor is the power source and can be a stepper motor or servo motor. These motors can precisely rotate a certain angle or number of revolutions according to control signals. The transmission mechanism converts the motor's rotational motion into linear movement of the beam splitter or focusing lens, ensuring precision and stability. The control system receives commands and controls the operation of the motor, achieving precise control of the position and distance between the beam splitter and focusing lens. Changing the distance between the beam splitter and focusing lens is primarily intended to optimize the performance of the optical system. In different inspection scenarios or for back-drilled holes of varying sizes, appropriate optical spacing ensures optimal light transmission between the beam splitter and focusing lens, thereby achieving accurate light band separation, direction adjustment, and focusing. For example, when inspecting back-drilled holes with larger diameters, the distance between the beam splitter and focusing lens needs to be increased to allow for more complete beam expansion and adjustment, ensuring accurate focus within the back-drilled hole.

[0063] In the embodiment of the present application, by adjusting the distance between the beam splitter and the focusing mirror, the propagation path and angle of the light can be changed, so that the polychromatic light can be more effectively decomposed into light beams including multiple different bands at the beam splitter, and these light beams can be incident on the focusing mirror in a suitable direction, ultimately achieving accurate light focusing and incidence on the back-drilled hole.

[0064] The circuit board inspection device provided in the embodiments of the present application can adjust the distance between the beam splitter and focusing lens to better match the optical system to the inspection conditions for back-drilled holes of varying sizes or with varying inspection accuracy requirements. For example, when inspecting tiny back-drilled holes with high precision, precisely adjusting the distance can improve the focusing accuracy of the light, thereby enhancing the accuracy of stump length measurement.

[0065] In some embodiments, the circuit board measuring device further includes: a second driving assembly, the second driving assembly being configured to be connected to the optical lens module and configured to drive the optical lens module to move in a direction parallel to the surface of the circuit board.

[0066] In an embodiment of the present application, a second drive assembly drives the movement of the optical lens module: the second drive assembly is connected to the optical lens module and can drive it to move in a direction parallel to the surface of the circuit board. This allows the optical lens module to reach different detection positions on the circuit board and perform multi-position detection of back-drilled holes. At the same time, the spectrometer measures the length of the back-drilled hole stumps at multiple detection positions. After obtaining the stump length data for multiple detection positions, the spectrometer compares these data and determines the smallest stump length as the target stump length.

[0067] The circuit board measuring device provided in the embodiment of the present application can eliminate some abnormal data caused by local process fluctuations or detection errors through multi-position detection, so that the target parameters finally determined can better represent the actual quality level of the circuit board.

[0068] In some embodiments, the circuit board measuring device further includes: a mobile platform for placing the circuit board and driving the circuit board to move, so as to determine target parameters of multiple detection positions.

[0069] In this embodiment of the present application, the mobile platform is used to place the circuit board and drive the circuit board to move. Similar to driving the movement of the optical lens module, its purpose is also to ensure that different back-drilled holes on the circuit board are sequentially within the detection range of the optical lens module, achieving multi-position detection.

[0070] The circuit board detection circuit provided in the embodiment of the present application realizes multi-position detection through a second drive component or a mobile platform, and a method for determining target parameters can improve the accuracy and comprehensiveness of the detection of target parameters of back drilling holes in the circuit board, and provide a more reliable basis for the quality control of the circuit board.

[0071] In some embodiments, the measuring device further includes a filter device, which is disposed in the optical path between the optical lens module and the spectrometer. The filter device is provided with filter micropores for filtering out stray light of non-focus wavelengths.

[0072] In the embodiment of the present application, the focal wavelength is the wavelength component that forms the smallest light spot (diameter <10μm) at the target position, and its reflected light can be efficiently collected by the optical system and transmitted to the spectrometer. The non-focal wavelength is the wavelength component that is not focused at the target position of the back-drilled hole due to dispersion. Its reflected light diverges in space, and some light cannot enter the subsequent optical path, forming stray light. For example, when measuring the length of a stump, light with wavelength components that are not focused in the dielectric layer and the signal layer is stray light of the non-focal wavelength. When measuring the drilling depth of a back-drilled hole, light with wavelength components that are not focused at the bottom of the back-drilled hole is stray light of the non-focal wavelength. That is, the filter device is used to allow the reflected light of the focal wavelength to pass through and filter out the stray light of the non-focal wavelength.

[0073] In the embodiment of the present application, the aperture size of the filtering micropores is generally 10-50 μm.

[0074] The circuit board measuring device provided in the embodiment of the present application can improve the signal-to-noise ratio and measurement accuracy by providing an optical filter device.

[0075] Based on the circuit board measuring devices provided in the aforementioned embodiments, an embodiment of the present application provides a circuit board measuring method, wherein the circuit board has a back-drilled hole, and the circuit board has a dielectric layer and a signal layer. The circuit board measuring method can be used for electronic devices, and the electronic device can be a spectrometer controller, or a mobile phone, tablet computer, etc.

[0076] Figure 8 A schematic diagram of the implementation flow of a circuit board measurement method provided in an embodiment of the present application is shown as follows: Figure 8 Shown, including: Step S601 : controlling a polychromatic light source to generate polychromatic light, so as to form a polychromatic light beam in the back-drilled hole, wherein the polychromatic light beam includes light beams of multiple different wavelength bands.

[0077] In an embodiment of the present application, a polychromatic light source can be turned on to generate polychromatic light containing multiple wavelength components according to preset parameters (such as light intensity, spectral range, etc.). After the polychromatic light source is generated, the fiber optic lens module can divide it into light beams including multiple different wavelength bands, and focus the light beams including multiple different wavelength bands and then inject them into the back-drilled hole along a first optical path to be reflected on the surface of the target position of the back-drilled hole to form reflected light. The module is also used to receive and focus the reflected light formed after the reflection of the light beam of at least one wavelength band, and then emit the reflected light along a second optical path.

[0078] Step S602 : receiving reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of a backdrilling hole in the circuit board according to spectral information of the reflected light.

[0079] In this embodiment of the present application, when measuring the stump length of a back-drilled hole, after the polychromatic light is processed by the optical lens module, some of the light enters the back-drilled hole and reflects off the dielectric layer and signal layer, generating two beams of reflected light. The spectrometer analyzes the spectral information of these two beams of reflected light to calculate the stump length of the back-drilled hole.

[0080] When measuring the depth of a back-drilled hole, after the polychromatic light is processed by the optical lens module, some of the light enters the back-drilled hole and reflects at the bottom, generating reflected light. The spectrometer analyzes the spectral information of this reflected light to calculate the back-drilled hole depth.

[0081] The circuit board measurement method provided in the embodiment of the present application generates polychromatic light by controlling a polychromatic light source. At this time, the circuit board measurement device can obtain the reflected light formed after receiving the reflection of a light beam of at least one band, and determine the target parameters of the back-drilled hole in the circuit board based on the spectral information of the reflected light, thereby realizing non-contact, high-precision measurement of the back-drilled hole.

[0082] In some embodiments, the target parameter includes a drilling depth of the backdrilled hole; Step S602 can be implemented by the following steps: Step S6021, receiving a first reflected light formed by reflection of a light beam of a wavelength band in the polychromatic light beam; Step S6022: Determine the drilling depth of the back-drilled hole according to the spectral information of the first reflected light.

[0083] In the embodiment of the present application, a specific wavelength may correspond to a different drilling depth, and after the spectral information is acquired, the drilling depth of the back-drilled hole may be calculated based on the wavelength.

[0084] In some embodiments, the target parameter includes the stump length of the back-drilled hole; Step S602 can be implemented by the following steps: Step S6023: receiving a second reflected light formed by reflection of the two wavelength bands of the polychromatic light beam.

[0085] In an embodiment of the present application, the circuit board includes: a dielectric layer and a signal layer, and the second reflected light includes: a first sub-reflected light and a second sub-reflected light, the first sub-reflected light is the reflected light of the dielectric layer in the back-drilled hole, and the second sub-reflected light is the reflected light of the signal layer in the back-drilled hole.

[0086] Step S6024: determining the length of the residual pile of the back-drilled hole according to the spectrum information of the second reflected light.

[0087] In the embodiment of the present application, an optical path difference is calculated based on spectral information of the first sub-reflected light and spectral information of the second sub-reflected light; and a length of the residual pile of the back-drilled hole is calculated based on the optical path difference.

[0088] In an embodiment of the present application, during optical measurement, when light enters a back-drilled via, it is reflected from the dielectric layer and the signal layer. The first and second sub-reflected beams correspond to reflected light from different locations (the dielectric layer and the signal layer), respectively. Since the propagation speed of light in a medium is related to the medium's refractive index, and the stump length causes the optical path lengths of the two reflected beams to differ, analyzing their spectral information allows the optical path difference to be calculated, thereby deriving the stump length. A spectrometer can detect the spectral information of the first and second sub-reflected beams, which includes parameters such as wavelength and intensity. Light of different wavelengths exhibits different propagation characteristics in an optical system. Spectral analysis techniques, such as Fourier transforms, can be used to extract information related to the optical path length from the spectral information. Due to the different optical path lengths of the two reflected beams, their spectra exhibit phase differences. By analyzing the manifestation of this phase difference at different wavelengths, the optical path difference can be calculated. For example, for light of a specific wavelength, there is a definite relationship between the phase change and the optical path difference. By measuring the phase change at multiple wavelengths, the optical path difference can be accurately calculated. The formula for calculating the optical path difference is known as optical path difference = 2 × n × L (where n is the refractive index of the dielectric layer, L is the stump length, and the multiplication by 2 accounts for the round-trip propagation of light). After calculating the optical path difference, combined with the known refractive index n of the dielectric layer, the stump length of the backdrilled hole can be calculated.

[0089] The circuit board measuring device provided in the embodiment of the present application does not need to directly contact the back-drilled hole, thus avoiding damage to the back-drilled hole caused by contact. It is also suitable for some difficult-to-contact or precise circuit board detection scenarios.

[0090] In some embodiments, step S602 may also be implemented by the following steps: Step S6025 , a plurality of detection positions are spaced apart in the back-drilled hole along the horizontal direction of the circuit board.

[0091] Step S6026: Control the optical lens module and the circuit board to move relative to each other along the surface of the circuit board, and obtain reflected light from multiple detection positions respectively.

[0092] In an embodiment of the present application, the aforementioned second drive assembly can be used to drive the movement of the optical lens module, or a mobile platform can be used to drive the movement of the circuit board to achieve relative movement of the two along the surface of the circuit board. During the movement process, the step size and direction of the movement need to be precisely controlled to ensure that all back-drilled hole positions that need to be detected on the circuit board can be covered. At each detection position, a polychromatic light source is used to generate polychromatic light. After processing by the optical lens module, in an embodiment of the present application, the optical lens module or the circuit board can be driven to perform step scanning along the diameter direction of the back-drilled hole (usually the X / Y axis). For example, when the aperture is 100um, the step size is 1um for scanning. N points are evenly collected in the diameter direction to ensure coverage from the edge of the hole to the center area to avoid the influence of local defects (such as burrs and uneven copper plating).

[0093] Step S6027 , obtaining corresponding detection parameters of the plurality of back-drilled holes according to the plurality of reflected lights.

[0094] In the embodiment of the present application, the detection parameters include: the length of the residual pile or the drilling depth of the back drilling hole.

[0095] Step S6028: determining target parameters for back drilling in the circuit board based on the detection parameters.

[0096] In an embodiment of the present application, outliers in the detection parameters corresponding to multiple detection positions can be removed to obtain screening detection parameters, wherein the deviation between the outliers and other detection parameters is greater than a deviation threshold; and the target parameters of the back drilling hole are determined based on the screening detection parameters.

[0097] In an embodiment of the present application, the mean μ and standard deviation σ of the drilling depths at multiple detection positions can be calculated, and outliers can be eliminated using the mean and standard deviation. For example, a drilling depth that differs greatly from the mean is an outlier and is removed. Figure 9 A schematic diagram of determining the drilling depth of multiple detection positions in a back-drilled hole provided in an embodiment of the present application is shown as follows: Figure 9 As shown, the drilling depths of multiple detection positions can be obtained by moving the position of the optical lens module. The algorithm can remove abnormal values ​​and retain values ​​with high reliability, thereby obtaining multiple screening detection parameters.

[0098] In the embodiment of the present application, with respect to the stump length, the minimum stump length can be selected as the target stump length, which can, to a certain extent, eliminate data on larger stump lengths caused by local process anomalies or detection errors, and more accurately reflect the overall quality stability of the circuit board. During the manufacture and detection of circuit boards, the stump lengths of back-drilled holes may vary due to factors such as fluctuations in the manufacturing process and different drilling positions. By controlling the relative movement of the optical lens module and the circuit board along the surface of the circuit board and measuring multiple detection positions, it is possible to fully understand the distribution of the back-drilled hole stump lengths on the entire circuit board, thereby accurately determining the target stump length and ensuring that the quality of the circuit board meets the requirements.

[0099] In an embodiment of the present application, with respect to the drilling depth, multiple screening detection parameters can be processed through original calculations (average value) to obtain a stable measurement value (drilling depth).

[0100] The method provided in the embodiment of the present application can fully grasp the target parameters of back drilling on the circuit board through multi-position detection, avoid missed detection or misjudgment that may occur due to only detecting a single position, and more accurately evaluate the quality of the circuit board.

[0101] In some embodiments, the optical lens module or circuit board can be driven to perform step scanning along the back-drilled hole diameter direction (usually X / Y axis) to obtain the drilling depth of multiple back-drilled holes. Figure 10 A schematic diagram of measuring the target drilling depth of multiple back-drilled holes provided in an embodiment of the present application is shown as follows: Figure 10 As shown, the contours of each back-drilled hole can be obtained by continuous scanning, and thus the target drilling depth of each back-drilled hole can be obtained based on the contours of each back-drilled hole. The method provided in the embodiment of the present application can accurately calculate the target drilling depth.

[0102] In some embodiments, the spectrometer and focusing lens in the optical lens module of the circuit board measuring device are liquid lenses, and the circuit board measuring device further includes: a first driving component. Before step S601, the method further includes: Step S6011: Obtain the diameter of the back-drilled hole and the back-drilled hole depth ratio.

[0103] In the embodiment of the present application, a high-precision optical measuring instrument, such as a laser scanning microscope, can be used to scan and measure the back-drilled hole to directly obtain its diameter data; the theoretical diameter value can also be obtained through relevant information in the circuit board design file, and appropriate corrections can be made based on actual manufacturing errors.

[0104] Step S6012: determining target voltages applied to the beam splitter and the focusing mirror based on the ratio of the diameter to the back-drilling depth, and determining the focal lengths of the beam splitter and the focusing mirror and their mutual distances in the optical system.

[0105] In embodiments of the present application, a database or mathematical model can be established that contains the relationships between back-drilled hole diameter, back-drilled hole depth ratio, target voltage, and mutual distance. Based on the acquired back-drilled hole diameter and back-drilled hole depth ratio, the target voltage applied to the beam splitter and focusing lens, as well as the focal length of the beam splitter and focusing lens and their mutual distance in the optical system, can be determined by querying the database or substituting the values ​​into the mathematical model.

[0106] Step S6013: Apply a target voltage to the beam splitter and the focusing mirror, and control the first driving component to adjust the focal lengths of the beam splitter and the focusing mirror to a mutual distance in the optical system. When the target voltage is applied to the beam splitter and the focusing mirror, and the focal lengths of the beam splitter and the focusing mirror to a mutual distance in the optical system, the light beam focused by the focusing mirror can be incident into the back-drilled hole, and the focus can adapt to different drilling depth measurements of the back-drilled hole.

[0107] In the embodiments of the present application, a voltage control circuit accurately applies a predetermined target voltage to the beam splitter and focusing lens, causing their refractive indices to change accordingly. Furthermore, a first drive assembly can be activated to precisely adjust the focal lengths of the beam splitter and focusing lens in the optical system according to their relative distance, ensuring that the adjusted distances are consistent with their relative distances.

[0108] In the embodiments of this application, the beam splitter and focusing lens are liquid lenses. Based on the principles of electrowetting or the electrorheological effect, a voltage applied to the liquid lens changes the interfacial tension between the liquid and the electrodes, causing the liquid to change shape and, in turn, the refractive index of the liquid lens. Back-drilled vias of different diameters require different light propagation characteristics, and these requirements can be met by adjusting the voltage to change the refractive index.

[0109] In the embodiments of this application, the distance between the beam splitter and the focusing lens affects the light propagation path and focusing effect. For back-drilled holes of different diameters, this distance needs to be adjusted so that the light beam, after being split and adjusted by the beam splitter and focused by the focusing lens, can accurately enter the back-drilled hole, ensuring effective reception of the optical signal and accuracy of subsequent detection.

[0110] In the embodiments of the present application, by obtaining the key parameter of the back-drilled hole diameter, and because back-drilled holes of different diameters have different requirements for light incidence and focusing, it is necessary to determine the target voltage for the beam splitter and focusing mirror, as well as the target distance between them, based on the diameter. The target voltage is then applied to the beam splitter and focusing mirror to change their refractive indices. Simultaneously, a first drive assembly is used to adjust the focal lengths of the beam splitter and focusing mirror to their relative distance in the optical system. This ensures that the light beam focused by the focusing mirror accurately enters the back-drilled hole, laying the foundation for subsequent operations such as accurately detecting the stump length.

[0111] The method provided in the embodiments of this application precisely adjusts optical parameters (voltage and distance) based on the back-drilled hole diameter, enabling light to better adapt to the geometric characteristics of the back-drilled hole, reducing light loss and errors during propagation, and thereby improving the accuracy of measurements of parameters such as stump length. This enables the measurement device to adapt to back-drilled holes of varying diameters, expanding the device's applicability. It eliminates the need for specialized optical modules for different back-drilled hole diameters, reducing equipment cost and ease of use. This ensures the beam's accurate entry into the back-drilled hole, improving light energy utilization efficiency and making the reflected light signal stronger and more stable, facilitating accurate analysis of the reflected light's spectral information by the spectrometer.

[0112] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0113] Figure 11 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 11 As shown, the electronic device 7 of this embodiment may include: at least one processor 30 ( Figure 7 Only one processor 30 is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on at least one processor 30. When the processor 30 executes the computer program 32, the steps in any of the above-mentioned method embodiments are implemented, or when the processor 30 executes the computer program 32, the functions of the modules / units in the above-mentioned apparatus or system embodiments are implemented.

[0114] For example, the computer program 32 may be divided into one or more modules / units, one or more of which are stored in the memory 31 and executed by the processor 30 to implement the present application. The one or more modules / units may be a series of computer program 32 instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the electronic device 7.

[0115] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program 32. When the computer program 32 is executed by the processor 30, the steps in the above-mentioned method embodiments can be implemented.

[0116] An embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0117] An embodiment of the present application provides a spectrometer, including the above-mentioned electronic device.

[0118] The embodiment of the present application provides a back drilling measurement system. Figure 12 A schematic diagram of a back drilling measurement system provided in an embodiment of the present application is shown in FIG. Figure 12 As shown, the system includes: an optical lens module and a spectrometer, and the optical lens module 10 is communicatively connected to the spectrometer 104 via an optical fiber.

[0119] In the embodiments of the present application, if the integrated unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the process steps in the above-described method embodiments can be implemented by computer program 32 instructing the relevant hardware. Computer program 32 can be stored in a computer-readable storage medium. When executed by processor 30, computer program 32 can implement the steps of each of the above-described method embodiments. Computer program 32 includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. Computer-readable media can include at least: any entity or device capable of carrying computer program code to a terminal, recording media, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunication signals, and software distribution media. Examples include USB flash drives, removable hard drives, magnetic disks, or optical disks. In some jurisdictions, based on legislation and patent practice, computer-readable media cannot be electric carrier signals or telecommunication signals.

[0120] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0121] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0122] In the embodiments provided in this application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0124] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A circuit board measuring device, characterized in that: The circuit board has a back-drilled hole, and the measuring device of the circuit board includes: a polychromatic light source configured to emit polychromatic light; an optical lens module configured to receive the polychromatic light, split the polychromatic light into light beams comprising a plurality of different wavelength bands, focus the light beams comprising the plurality of different wavelength bands, and then project them into the back-drilled hole along a first optical path to reflect them on a surface at a target position of the back-drilled hole to form reflected light; and to receive and focus the reflected light formed by reflection of light beams of at least one wavelength band, and then emit the reflected light along a second optical path; a spectrometer, disposed in the second optical path, for splitting the reflected light; A spectrometer is used to determine target parameters of the back-drilled hole according to spectral information of the reflected light after spectroscopy.

2. The circuit board measuring device according to claim 1, wherein: The optical lens module includes a beam splitter and a focusing lens; The beam splitter is used to split the polychromatic light into the light beams comprising the plurality of different wavelength bands, and adjust the propagation directions of the light beams comprising the plurality of different wavelength bands along the propagation direction of the first optical path, wherein the propagation direction of the first optical path is perpendicular to the axis of the back-drilled hole, and to allow the light beams comprising the plurality of different wavelength bands to be incident on the focusing mirror, and is further used to receive reflected light formed by reflection of the light beam of at least one wavelength band and emit the reflected light along the second optical path; The focusing mirror is used to focus the light beam of the at least one wavelength band and inject the focused light beam of the at least one wavelength band into the back-drilled hole, and is also used to receive and focus the light beam of the at least one wavelength band after reflection and transmit it to the spectroscope.

3. The circuit board measuring device according to claim 2, characterized in that: The optical lens module also includes a shaping module: The shaping module is arranged between the beam splitter and the focusing mirror, and is used to adjust the optical path of the light beam.

4. The circuit board measuring device according to claim 2, wherein: The beam splitter and the focusing lens are liquid lenses, and the refractive index of the liquid lens can be changed by changing the voltage applied to the liquid lens.

5. The circuit board measuring device according to claim 2, wherein: The circuit board measuring device further includes: a first driving component connected to the spectroscope and / or focusing mirror, and configured to drive the spectroscope and / or focusing mirror to move so as to change the distance between the spectroscope and the focusing mirror.

6. The circuit board measuring device according to claim 1, wherein: The polychromatic light source comprises: a light source for generating monochromatic laser light of a preset wavelength; The atomic luminescent phosphor is used to emit light under the irradiation of the monochromatic laser to generate complex light, wherein the light intensity difference between any two lights in the complex light is less than a preset threshold.

7. The circuit board measuring device according to claim 1, wherein: The measuring device for the circuit board also includes: a second driving component, which is used to connect to the optical lens module and drive the optical lens module to move in a direction parallel to the board surface of the circuit board to determine the target parameters of multiple detection positions.

8. The circuit board measuring device according to claim 1, wherein: The circuit board measuring device further comprises: a moving platform, the moving platform is used to place the circuit board, and the moving platform is used to drive the circuit board to move so as to determine target parameters of multiple detection positions.

9. The circuit board measuring device according to claim 1, wherein: The measuring device for the circuit board further comprises a filter device, which is arranged in the optical path between the optical lens module and the spectrometer. The filter device is provided with filter micropores, which are used to filter out stray light of non-focus wavelengths.

10. A method for measuring a circuit board, characterized in that: The circuit board has a back-drilled hole, and the method is applied to the circuit board measurement device according to any one of claims 1 to 9, comprising: controlling a polychromatic light source to generate polychromatic light, so as to form a polychromatic light beam in the back-drilled hole, wherein the polychromatic light beam includes light beams of multiple different wavelength bands; Reflected light formed by reflection of a light beam of at least one wavelength band is received, and target parameters of a back-drilled hole in the circuit board are determined according to spectral information of the reflected light.

11. The method for measuring a circuit board according to claim 10, wherein: The target parameters include the drilling depth of the back-drilled hole; The receiving of reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of the back drilling hole in the circuit board according to spectral information of the reflected light, includes: receiving a first reflected light formed by reflection of a light beam of a wavelength band in the polychromatic light beam; The drilling depth of the back-drilled hole is determined according to the spectral information of the first reflected light.

12. The method for measuring a circuit board according to claim 10, wherein: The target parameters include the length of the stump of the back-drilled hole; The receiving of reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of the back drilling hole in the circuit board according to spectral information of the reflected light, includes: receiving a second reflected light formed by reflection of the light beams of two wavelength bands in the polychromatic light beam; The length of the stump of the back-drilled hole is determined according to the spectral information of the second reflected light.

13. The circuit board measuring method according to claim 12, characterized in that: The circuit board includes: a dielectric layer and a signal layer; the second reflected light includes: a first sub-reflected light and a second sub-reflected light; the first sub-reflected light is reflected light from the dielectric layer in the back-drilled hole; the second sub-reflected light is reflected light from the signal layer in the back-drilled hole; and determining the stump length of the back-drilled hole based on spectral information of the second reflected light includes: calculating an optical path difference based on spectral information of the first sub-reflected light and spectral information of the second sub-reflected light; The stump length of the back-drilled hole is calculated based on the optical path difference.

14. The method for measuring a circuit board according to claim 11, wherein: The receiving of reflected light formed by reflection of a light beam of at least one wavelength band, and determining target parameters of the back drilling hole in the circuit board according to spectral information of the reflected light, includes: A plurality of detection positions are arranged at intervals in the back-drilled hole along the horizontal direction of the circuit board; Controlling the optical lens module and the circuit board to move relative to each other along the surface of the circuit board to obtain reflected light from a plurality of detection positions; Obtaining corresponding detection parameters of a plurality of back-drilled holes according to the plurality of reflected lights; Target parameters for back drilling in the circuit board are determined based on the detection parameters.

15. The method for measuring a circuit board according to claim 14, wherein: The determining, based on the detection parameters, target parameters for back drilling in the circuit board includes: removing abnormal values ​​from the detection parameters corresponding to the plurality of detection positions to obtain screening detection parameters, wherein a deviation between the abnormal value and the other detection parameters is greater than a deviation threshold; Target parameters of the backdrilling hole are determined based on the screening detection parameters.

16. The method for measuring a circuit board according to claim 10, wherein: The spectrometer and focusing lens in the optical lens module of the circuit board measuring device are liquid lenses. The circuit board measuring device further includes: a first driving component. The method further includes: Obtaining a diameter of the back-drilled hole and a back-drilled hole depth ratio; Determining target voltages applied to the beam splitter and the focusing mirror based on the ratio of the diameter to the back-drilled hole depth, and determining a mutual distance between the focal lengths of the beam splitter and the focusing mirror in the optical system; The target voltage is applied to the beam splitter and the focusing mirror, and the first driving component is controlled to adjust the distance between the focal lengths of the beam splitter and the focusing mirror in the optical system to the mutual distance. When the target voltage is applied to the beam splitter and the focusing mirror, and the distance between the focal lengths of the beam splitter and the focusing mirror in the optical system is the mutual distance, the light beam focused by the focusing mirror can be incident into the back-drilled hole, and the focus can adapt to different drilling depth measurements of the back-drilled hole.

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