A device and method for measuring the depth of copper layer of a printed circuit board

Abstract

The present invention relates to the field of printed circuit board back drilling technology, and in particular to a printed circuit board copper layer depth measurement device and a measurement method thereof, comprising a base, a workbench, a measuring component, a moving component and a processor. This solution uses a dual CCD lens module to perform cross-positioning compensation on the detection hole position, and combines a contact displacement sensor to measure the local board thickness in real time, effectively eliminating the influence of uneven substrate thickness; a dual semi-lens module is used to optimize the optical path, enhance the intensity of the reflected light signal, and ensure the stability of the optical measurement; the conical reflective film at the end of the probe accurately guides the light to the copper layer of the hole wall, and non-contact ranging is achieved by capturing the reflected light signals twice, and finally the precise inner layer copper depth is calculated by the processor. This method avoids mechanical contact damage while ensuring high precision, significantly improving measurement efficiency and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board back drilling, in particular to a printed circuit board copper layer depth measuring device and a measuring method thereof. Background Art

[0002] In multilayer printed circuit board (PCB) manufacturing, the backdrilling process is used to drill holes from the backside (or a specific side) of the PCB toward the vias. Precisely controlling the drill depth removes only the residual stubs, preserving the effective transmission segments without damaging the circuitry on other layers. Traditionally, a fixed, preset drill depth has been used to process an entire batch of PCBs. However, due to thickness tolerances within the PCB substrate and the potential for uneven thickness during the lamination process, a uniform drill depth can easily lead to overdrilling on some boards, damaging inner-layer circuitry, or incomplete removal of residual copper tails.

[0003] Existing measurement techniques often involve slicing and damaging the material itself. Samples are sliced ​​and then, through windowing, the copper layer position is measured using measuring instruments. This method often causes damage to the material. Therefore, a method that can adapt to fluctuations in plate thickness and accurately measure the position of inner copper layers is urgently needed. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above problems in the prior art, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is to overcome the defects of inaccurate drilling depth control caused by board thickness differences in the existing PCB backdrilling process, and the defects that traditional measurement methods are easily interfered with or damaged.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: A printed circuit board copper layer thickness measuring device, comprising a base; a workbench, comprising a first clamping plate, a second clamping plate, and a frame, the first clamping plate and the second clamping plate being arranged vertically and slidingly arranged on the frame, and the frame slidingly cooperates with the base; a measuring component, comprising a first slide seat and a second slide seat, the first slide seat and the second slide seat being respectively arranged on opposite sides of the workbench and slidingly cooperate with the base; a probe is provided on the first slide seat, and a first CCD lens module, a light source emitter, and a half-lens module are provided on the second slide seat, the half-lens module is located above the first CCD lens module, the light source emitter is arranged at one end of the half-lens module, and the probe and the first CCD lens module are both arranged vertically with the workbench; a moving component is arranged between the workbench, the first slide seat, the second slide seat and the base, and can drive the workbench, the first slide seat, and the second slide seat to move; a processor, electrically connected to the first CCD lens module.

[0008] As a preferred solution of the printed circuit board copper layer depth measuring device described in the present invention, wherein: the half-mirror module includes a shell, a first half-mirror, and a second half-mirror; the shell is provided with an incident light inlet and a bidirectional light path outlet, the incident light inlet is configured to be aligned with the optical axis of the light source emitter, and the bidirectional light path outlet is arranged through the shell, the first half-mirror is fixedly provided at the incident light inlet, and its reflecting surface is facing the inside of the shell at a preset inclination angle, and the second half-mirror is fixedly provided at the bidirectional light path outlet, and its reflecting surface is opposite to the reflecting surface of the first half-mirror.

[0009] As a preferred solution of the printed circuit board copper layer depth measuring device described in the present invention, the moving component includes a first mover and a first stator, the first mover is arranged on the workbench, the first slide seat, and the second slide seat, and the first stator is arranged on the base.

[0010] As a preferred solution of the printed circuit board copper layer depth measuring device described in the present invention, the first clamping plate and the second clamping plate are both driven by a belt, and the driving wheel of the belt drive is connected to the output end of the motor; the first clamping plate, the second clamping plate, and the inner side of the frame are all provided with a placement plate.

[0011] As a preferred solution of the printed circuit board copper layer depth measuring device described in the present invention, the first slide seat is also provided with a first slide, a second mover, and a second stator. The first slide is arranged on the side of the first slide seat away from the probe, and slides with the first slide seat. The probe is arranged on the first slide, the second mover is arranged on the first slide, and the second stator is arranged on the first slide seat.

[0012] As a preferred solution of the printed circuit board copper layer depth measuring device described in the present invention, wherein: the second slide seat is also provided with a second slide, a third mover, and a third stator, the second slide and the second slide seat are slidably matched, the first CCD lens module, the light source emitter, and the semi-mirror module are all arranged on the second slide, the third mover is arranged on the second slide, and the third stator is arranged on the second slide seat.

[0013] As a preferred solution of the printed circuit board copper layer depth measuring device of the present invention, a contact displacement sensor is further provided on the first slide, and the contact displacement sensor is provided on one side of the probe.

[0014] As a preferred solution of the printed circuit board copper layer depth measuring device of the present invention, a second CCD lens module is further provided on the first slide, and the second CCD lens module is provided on one side of the probe.

[0015] The present invention also proposes a method for measuring the inner layer depth of a printed circuit board, comprising the following steps: clamping and positioning the PCB, controlling a motor to drive a first clamping plate and a second clamping plate based on the PCB size to form a clamping space with a 1-2 mm offset gap; after placing the PCB, switching the motor to a torque control mode and clamping to a preset torque threshold;

[0016] Detection hole position compensation: the actual position of the detection hole is collected by the first CCD lens module and the second CCD lens module, and the processor generates coordinate compensation data and updates the movement path;

[0017] Contact-type board thickness measurement: drives the contact displacement sensor to contact the PCB surface around the detection hole to obtain the real-time board thickness value H1;

[0018] Optical multi-stage detection: drive the probe 311 into the detection hole and project light onto the hole wall through its lower end; record the probe 311 position Z1 when the surface copper ring reflects the first ring-shaped reflected light; record the probe 311 position Z3 when the bottom copper ring reflects the third ring-shaped reflected light; continue to move the probe 311 until the inner copper ring reflects the second ring-shaped reflected light, and record the probe 311 position Z2;

[0019] Optical plate thickness verification, the processor calculates the optical plate thickness value H2=|Z3-Z1|;

[0020] Data validity judgment: when |H1-H2| / H1>preset threshold, the detection hole data is judged to be invalid and an alarm signal is issued;

[0021] Calculate the inner copper depth. If the data is valid, the processor calculates the moving distance ΔZ = |Z2-Z1|, where ΔZ is the inner copper depth.

[0022] Perform full-area scanning, move the workbench and the first and second slides according to the compensated path, and traverse all detection holes to perform the above steps.

[0023] The beneficial effects of the present invention are as follows: It uses a dual CCD lens module to perform cross-positioning compensation on the detection hole position, and combines it with a contact displacement sensor to measure the local plate thickness H1 in real time. It uses a dual semi-lens module to improve optical path efficiency, allowing the probe's cone reflective film to accurately guide light to the hole wall. By capturing the three-level reflected light signals from the surface copper ring Z1, the bottom copper ring Z3, and the inner copper ring Z2, it simultaneously calculates the optical plate thickness H2 = |Z3 - Z1|. A processor compares the deviation values ​​of H1 and H2 to determine data validity, automatically identifying hole wall defects or plate defects and issuing an alarm, ensuring that the depth gauge D = H1 - |Z2 - Z1| outputs only based on valid data. This method, while ensuring measurement accuracy, establishes a dual quality assurance mechanism of contact measurement and optical verification, significantly improving the reliability of backdrill depth control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. Among them:

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the workbench structure of the present invention;

[0027] Figure 3 This is a schematic diagram of the back structure of the workbench of the present invention;

[0028] Figure 4 This is a schematic diagram of the internal structure of the semi-mirror module of the present invention;

[0029] Figure 5 This is a schematic structural diagram of the first sliding platform of the present invention;

[0030] Figure 6This is a schematic diagram of the back structure of the first slide seat of the present invention;

[0031] Figure 7 This is a schematic structural diagram of the second slide seat of the present invention;

[0032] Figure 8 This is a schematic diagram of the back structure of the second slide seat of the present invention;

[0033] Figure 9 The present invention is a flow chart of a measurement method of a device for measuring the depth of copper layer of a printed circuit board.

[0034] In the figure: 1. base; 2. workbench; 21. first clamping plate; 22. second clamping plate; 23. frame; 3. measuring component; 31. first slide seat; 32. second slide seat; 311. probe; 321. first CCD lens module; 322. light source emitter; 323. half-mirror module; 4. moving component; 3231. shell; 3232. first half-mirror; 3233. second half-mirror; 3234. incident light entrance; 3235. bidirectional light path exit; 41. first mover; 25. motor; 24. placement plate; 312. first slide; 313. second mover; 314. second stator; 324. second slide; 325. third mover; 326. third stator; 315. contact displacement sensor; 316. second CCD lens module. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0038] In the printed circuit board copper layer depth measurement device, the spatial rectangular coordinate system is established according to the following rules: X-axis direction: parallel to the movement direction of the first slide 31 and the second slide 32, defined as the width direction of the printed circuit board (PCB); Y-axis direction: parallel to the movement direction of the workbench 2 relative to the base 1, defined as the length direction of the PCB; Z-axis direction: perpendicular to the bearing plane of the workbench 2, and consistent with the axial direction of the probe 311 and the first CCD lens module 321, defined as the thickness direction of the PCB.

[0039] Example 1, reference Figures 1 to 8 , which is the first embodiment of the present invention, and provides a device for measuring the depth of the copper layer of a printed circuit board. The device for measuring the depth of the copper layer of a printed circuit board includes a base 1; a workbench 2, including a first clamping plate 21, a second clamping plate 22, and a frame 23, wherein the first clamping plate 21 and the second clamping plate 22 are vertically arranged and slidably arranged on the frame 23, and the frame 23 is slidably matched with the base 1; a measuring component 3, including a first slide seat 31 and a second slide seat 32, wherein the first slide seat 31 and the second slide seat 32 are respectively arranged on opposite sides of the workbench 2 and slidably matched with the base 1; a probe 311 is provided on the first slide seat 31, and a probe 311 is provided on the second slide seat 32 is provided with a first CCD lens module 321, a light source emitter 322, and a half-mirror module 323, wherein the half-mirror module 323 is located above the first CCD lens module 321, and the light source emitter 322 is provided at one end of the half-mirror module 323. The probe 311 and the first CCD lens module 321 are both arranged perpendicular to the workbench 2; a moving component 4 is arranged between the workbench 2, the first slide seat 31, the second slide seat 32 and the base 1, and can drive the workbench 2, the first slide seat 31, and the second slide seat 32 to move; a processor is electrically connected to the first CCD lens module 321;

[0040] The base 1 is the supporting platform of the device, providing an installation reference for the workbench and measuring components; the first clamp 21 / the second clamp 22 jointly clamps and fixes the PCB board, the frame 23 limits the PCB placement area, and slides with the base 1 to realize Y-axis movement; the first slide seat 31 and the second slide seat 32 are X-axis moving platforms, so that the detection range covers the entire detection hole of the PCB, avoiding the blind spot of a single CCD viewing angle; it is worth noting that the end of the probe 311 is a cone and covered with a reflective film, guiding the light to the wall of the detection hole, the first CCD lens module 321 is the main imaging unit, capturing the annular reflected light, the light source emitter 322 generates incident light, and the semi-mirror module 323 is used to receive and reflect the incident light. The processor calculates the drilling depth based on the moving distance between the first annular reflected light and the second annular reflected light reflected by the probe 311.

[0041] Specifically, 2. The half-mirror module 323 includes a housing 3231, a first half-mirror 3232, and a second half-mirror 3233. The housing 3231 is provided with an incident light inlet 3234 and a bidirectional light path outlet 3235. The incident light inlet 3234 is configured to be aligned with the optical axis of the light source emitter 322. The bidirectional light path outlet 3235 is provided through the housing 3231. The first half-mirror 3232 is fixedly provided at the incident light inlet 3234, with its reflective surface facing the interior of the housing at a preset inclination angle. The second half-mirror 3233 is fixedly provided at the bidirectional light path outlet 3235, with its reflective surface opposite to the reflective surface of the first half-mirror 3232.

[0042] The optical path is defined as: the incident light L1 emitted by the light source emitter 322 enters through the incident light entrance 3234; the incident light L1 is reflected by the first half-mirror 3232 to form a first reflected light L2; the first reflected light L2 is reflected twice by the second half-mirror 3233 to form a second reflected light L3; the second reflected light L3 passes through the two-way light path exit 3235 and irradiates the conical reflective film at the end of the probe 311; the conical reflective film projects the light to the target reflective surface of the wall of the test hole of the circuit board; the wall reflected light L4 directly penetrates the second half-mirror 3233 and enters the first CCD lens module 321.

[0043] A single half-mirror needs to process both the reflection of incident light and the transmission of reflected light at the same time, resulting in large light energy loss and stray light interference. The first half-mirror 3232 is responsible for efficiently reflecting incident light and retaining the light source energy to the maximum extent; the second half-mirror 3233 is responsible for directing the reflected light to the probe and optimizing the focusing of the light path by tilting the angle; preferably, in this embodiment, the first half-mirror 3232 and the second half-mirror 3233 are both set at 45°; the integrated design of the shell 3231 solidifies the first half-mirror 3232, the second half-mirror 3233 and the light path channel into a closed module, isolating them from external environmental light pollution and preventing mechanical vibration from causing optical axis deviation.

[0044] Specifically, the moving assembly 4 includes a first mover 41 and a first stator, the first mover 41 is arranged on the workbench 2, the first slide seat 31, and the second slide seat 32, and the first stator is arranged on the base 1;

[0045] Traditional screw transmission will produce cumulative errors due to wear after long-term operation. Therefore, this solution uses a linear motor to replace the ball screw to eliminate positioning drift caused by mechanical backlash.

[0046] Specifically, the first clamping plate 21 and the second clamping plate 22 are both driven by a belt, and the driving wheel of the belt drive is connected to the output end of the motor 25; the first clamping plate 21, the second clamping plate 22, and the inner side of the frame 23 are all provided with a placement plate 24;

[0047] It is worth noting that the motor 25 needs to have a torque mode, and the placement plate 24 places the PCB to prevent the PCB from being suspended and deformed.

[0048] Specifically, the first slide seat 31 is further provided with a first slide 312, a second mover 313, and a second stator 314. The first slide 312 is provided on a side of the first slide seat 31 away from the probe 311 and is slidably engaged with the first slide seat 31. The probe 311 is provided on the first slide 312, the second mover 313 is provided on the first slide 312, and the second stator 314 is provided on the first slide seat 31.

[0049] The first slide 312 and the first slide seat 31 can move relative to each other, driving the probe 311 to move along the Z direction, close to the detection hole. It is worth noting that a grating ruler is also provided on the first slide 312, which can measure the moving distance of the probe 311. This is an existing technology and will not be elaborated here.

[0050] Specifically, a second slide 324, a third mover 325, and a third stator 326 are further provided on the second slide seat 32. The second slide 324 is slidably matched with the second slide seat 32. The first CCD lens module 321, the light source emitter 322, and the semi-mirror module 323 are all provided on the second slide 324. The third mover 325 is provided on the second slide 324. The third stator 326 is provided on the second slide seat 32.

[0051] The third mover 325 and the third stator 326 are the Z-axis focusing mechanism of the first CCD lens module 321 , which dynamically compensate for the flatness tolerance of the PCB and ensure that the reflected light is always imaged at the optimal focal plane of the CCD.

[0052] Specifically, a contact displacement sensor 315 is further provided on the first slide 312 , and the contact displacement sensor 315 is provided on one side of the probe 311 ;

[0053] The contact displacement sensor 315 measures the board thickness H1 around the detection hole in real time, replacing the global average value to solve the problem of uneven PCB thickness distribution. In this solution, the contact displacement sensor 315 is model GT2-A50.

[0054] It is worth noting that the board thickness H1 is also used to detect whether the PCB and the detection hole are normal. When the drive probe 311 enters the detection hole, the light is projected onto the hole wall through its cone reflection film; when the surface copper ring reflects the first ring reflection light, the probe position Z1 is recorded; when the bottom copper ring reflects the third ring reflection light, the probe position Z3 is recorded; the probe is further moved to the inner copper ring and the position Z2 is recorded when the second ring reflection light is reflected; the processor calculates the optical board thickness value H2 = |Z3-Z1|; when |H1-H2| / H1> the preset threshold, the detection hole data is determined to be invalid and an alarm signal is issued;

[0055] Contact measurement H1 directly obtains the local physical thickness of the detection hole; optical measurement H2 calculates the theoretical thickness through the difference in reflection position between the surface copper Z1 and the bottom copper Z3; by comparing H2 with H1, measurement distortion caused by surface scratches, hole tilt or copper layer defects can be identified. The preset threshold is set by the user according to actual needs.

[0056] Specifically, a second CCD lens module 316 is further provided on the first slide 312 , and the second CCD lens module 316 is provided on one side of the probe 311 ;

[0057] It's worth noting that before testing, the system pre-loads the position information of the inspection holes on the PCB to be measured into the processor. This is conventional technology and will not be discussed in detail here. The first and second CCD lens modules 321 and 316 are then used to capture images of the actual positions of the inspection holes. The processor compares the preset coordinates of the inspection holes with the actual coordinates, generates position compensation data, and updates the movement paths of the worktable 2 and measurement assembly 3.

[0058] When in use, the workbench 2 clamps the PCB on the three-sided placement plate 24 through the motor 25 in torque control mode; the moving component 4 drives the workbench (Y-axis) and the first slide seat 31 and the second slide seat 32 (X-axis) to locate the target detection hole, the first CCD lens module 321 and the second CCD lens module 316 cooperate to capture the hole position image and the processor generates a compensation path; the contact displacement sensor 315 presses down to measure the local board thickness H1; the light source emitter 322 emits light, which is reflected by the first half-mirror 3232 to the second half-mirror 3233, and then illuminates the probe after secondary reflection. 311 cone reflective film; the probe enters the detection hole driven by the second mover 313, and the cone reflective film projects light onto the hole wall. When the surface copper ring part reflects the first ring light, the position Z1 is recorded. When it continues to probe down to the inner copper ring part and reflects the second ring light, the position Z2 is recorded. When the bottom copper ring part reflects the third ring reflected light, the probe position Z3 is recorded. The processor calculates the optical plate thickness value H2=|Z3-Z1|. When |H1-H2| / H1>the preset threshold, the detection hole data is determined to be invalid and an alarm signal is issued; if the data is valid, the processor calculates the inner copper depth ΔZ=|Z2-Z1|; the compensation path moving device traverses all detection holes to complete the measurement.

[0059] Example 2, reference Figure 9 This is the second embodiment of the present invention. This embodiment provides a method for measuring the depth of a copper layer on a printed circuit board, which is applicable to a device for measuring the depth of a copper layer on a printed circuit board. A method for using the device for measuring the depth of a copper layer on a printed circuit board is characterized by comprising the following steps:

[0060] S1: PCB positioning and clamping

[0061] Based on the size data of the PCB to be tested, the motor 25 of the workbench 2 is controlled to: drive the first clamping plate 21 and the second clamping plate 22 to slide along the frame 23 in position control mode, forming an offset clamping space 1-2 mm larger than the actual size of the PCB; place the PCB in the offset space, supported by the frame 23, the first clamping plate 21, and the placement plate 24 inside the second clamping plate 22; and switch the motor 25 to torque control mode, causing the first clamping plate 21 and the second clamping plate 22 to move synchronously toward each other until the output torque reaches a preset threshold, thereby completing the anti-deformation fixation of the PCB;

[0062] S2: Detection hole coordinate compensation

[0063] The workbench 2 is driven to move along the Y-axis by the moving assembly 4, and the first and second slides 31 and 32 are driven to move along the X-axis, so that the first CCD lens module 321 on the second slide 32 and the second CCD lens module 316 on the first slide 31 are aligned with the target detection holes on the PCB in sequence. The first and second CCD lens modules 321 and 316 are used to capture images of the actual positions of the detection holes, respectively. The processor compares the preset coordinates of the detection holes with the actual coordinates, generates position compensation data, and updates the movement path.

[0064] S3: Contact plate thickness measurement

[0065] Control the second mover 313 of the first slide seat 31 to drive the first slide 312 to descend along the Z axis, so that the contact displacement sensor 315 contacts the PCB surface around the detection hole; record the real-time board thickness value H1 measured by the contact displacement sensor 315;

[0066] S4: Optical multi-level measurement

[0067] Synchronously perform the following operations:

[0068] a control of the second slide seat 32 of the third mover 325 drives the second slide 324 along the Z axis fine-tuning, so that the first CCD lens module 321 completes the focus;

[0069] b start the light emitter 322, the incident light sequentially through the first half of the half lens module 323 3232, the second half of the half lens 3233 is reflected, irradiated to the end of the probe 311 of the cone reflective film;

[0070] c. The probe 311 is driven by the second mover 313 to enter the detection hole along the Z axis, and the cone reflective film projects light onto the hole wall;

[0071] When the surface copper ring reflects the first ring-shaped reflected light, the probe position Z1 is recorded; when the bottom copper ring reflects the third ring-shaped reflected light, the probe position Z3 is recorded; continue to move the probe until the inner copper ring reflects the second ring-shaped reflected light, and record the position Z2;

[0072] S5: Optical plate thickness verification

[0073] The processor calculates the optical plate thickness value H2=|Z3-Z1|;

[0074] S6: Data validity determination

[0075] When |H1-H2| / H1>the preset threshold, the detection hole data is deemed invalid and an alarm signal is issued to avoid the risk of misjudgment due to hole position deformation;

[0076] S7: Calculate inner layer copper depth

[0077] If the data is valid, the processor executes: Calculate the probe movement distance ΔZ = |Z2 - Z1|, where ΔZ is the inner layer copper depth value;

[0078] S8: Full Scan

[0079] Repeat steps S2-S7, and drive the workbench 2 and the first slide seat 31 and the second slide seat 32 to move according to the compensated path through the moving component 4 until the measurement of all the inspection holes of the PCB is completed.

[0080] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A device for measuring the depth of a copper layer on a printed circuit board, characterized in that: include, Base (1); A workbench (2) comprises a first clamping plate (21), a second clamping plate (22), and a frame (23), wherein the first clamping plate (21) and the second clamping plate (22) are vertically arranged and slidably arranged on the frame (23), and the frame (23) is slidably matched with the base (1); A measuring assembly (3) comprising a first slide seat (31) and a second slide seat (32), wherein the first slide seat (31) and the second slide seat (32) are respectively arranged on opposite sides of the workbench (2) and are slidably engaged with the base (1); A probe (311) is provided on the first slide seat (31), and a first CCD lens module (321), a light source emitter (322), and a half-lens module (323) are provided on the second slide seat (32), wherein the half-lens module (323) is located above the first CCD lens module (321), and the light source emitter (322) is provided at one end of the half-lens module (323). The probe (311) and the first CCD lens module (321) are both arranged perpendicular to the workbench (2); A moving component (4) is arranged between the workbench (2), the first slide seat (31), the second slide seat (32) and the base (1), and is capable of driving the workbench (2), the first slide seat (31), and the second slide seat (32) to move; A processor electrically connected to the first CCD lens module (321); The half-mirror module (323) comprises a shell (3231), a first half-mirror (3232), and a second half-mirror (3233). The shell (3231) is provided with an incident light inlet (3234) and a bidirectional light path outlet (3235). The incident light inlet (3234) is configured to be aligned with the optical axis of the light source emitter (322). The bidirectional light path outlet (3235) is provided through the shell (3231). The first half-mirror (3232) is fixedly provided at the incident light inlet (3234), with its reflection surface facing the interior of the shell at a preset inclination angle. The second half-mirror (3233) is fixedly provided at the bidirectional light path outlet (3235), with its reflection surface facing the reflection surface of the first half-mirror (3232).

2. The printed circuit board copper layer depth measuring device according to claim 1, wherein: The moving assembly (4) comprises a first mover (41) and a first stator, wherein the first mover (41) is arranged on the workbench (2), the first slide seat (31), and the second slide seat (32), and the first stator is arranged on the base (1).

3. The printed circuit board copper layer depth measuring device according to claim 2, characterized in that: The first clamping plate (21) and the second clamping plate (22) are both driven by a belt, and the driving wheel of the belt drive is connected to the output end of the motor (25); A placement plate (24) is provided on the inner sides of the first clamping plate (21), the second clamping plate (22), and the frame (23).

4. The printed circuit board copper layer depth measuring device according to claim 3, wherein: The first slide seat (31) is further provided with a first slide (312), a second mover (313), and a second stator (314). The first slide (312) is provided on a side of the first slide seat (31) away from the probe (311) and is slidably engaged with the first slide seat (31). The probe (311) is provided on the first slide (312), the second mover (313) is provided on the first slide (312), and the second stator (314) is provided on the first slide seat (31).

5. The printed circuit board copper layer depth measuring device according to claim 4, characterized in that: The second slide seat (32) is further provided with a second slide (324), a third mover (325), and a third stator (326); the second slide (324) is slidably matched with the second slide seat (32); the first CCD lens module (321), the light source emitter (322), and the semi-lens module (323) are all provided on the second slide seat (324); the third mover (325) is provided on the second slide seat (324); and the third stator (326) is provided on the second slide seat (32).

6. The printed circuit board copper layer depth measuring device according to claim 5, characterized in that: A contact displacement sensor (315) is also provided on the first slide (312), and the contact displacement sensor (315) is provided on one side of the probe (311).

7. The printed circuit board copper layer depth measuring device according to claim 6, characterized in that: A second CCD lens module (316) is also provided on the first slide (312), and the second CCD lens module (316) is provided on one side of the probe (311).

8. A method for measuring the depth of a copper layer of a printed circuit board, applicable to the device for measuring the depth of a copper layer of a printed circuit board according to claim 7, characterized in that: The following steps are involved: PCB clamping and positioning: based on the PCB size, the motor (25) is controlled to drive the first clamping plate (21) and the second clamping plate (22) to form a clamping space with a 1-2 mm offset gap; after placing the PCB, the motor is switched to a torque control mode and clamped to a preset torque threshold; Detection hole position compensation, collecting the actual position of the detection hole through the first CCD lens module (321) and the second CCD lens module (316), and the processor generates coordinate compensation data and updates the movement path; Contact type plate thickness measurement, driving the contact type displacement sensor (315) to contact the PCB surface around the detection hole to obtain a real-time plate thickness value H1; Optical multi-stage detection, driving the probe (311) into the detection hole, projecting light onto the hole wall through its lower end; recording the position Z1 of the probe (311) when the surface copper ring portion reflects the first ring-shaped reflected light; and recording the position Z3 of the probe (311) when the bottom copper ring portion reflects the third ring-shaped reflected light; Continue to move the probe (311) until the inner copper ring portion reflects the second ring-shaped reflected light, and record the position Z2; Optical plate thickness verification, the processor calculates the optical plate thickness value H2=|Z3-Z1|; Data validity judgment: when |H1-H2| / H1>preset threshold, the detection hole data is judged to be invalid and an alarm signal is issued; Calculate the inner layer copper depth. If the data is valid, the processor calculates the moving distance ΔZ = |Z2-Z1|, where ΔZ is the inner layer copper depth value. Perform full-area scanning, move the workbench (2) and the first slide seat (31) and the second slide seat (32) according to the compensated path, and traverse all the detection holes to perform the above steps.

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