A printed circuit board depth measurement dual lens system

Abstract

The utility model relates to optical measurement technical field, especially a kind of printed circuit board depth measurement double-lens system, including light source transmitter, half-transmission half-reflection mirror module, depth measurer and double-lens module. Double-lens module includes light splitting unit, first lens unit and second lens unit. Through the alternate sampling of double lens in time, even when the copper layer thickness is less than the moving distance of measurer unit time, complete optical signal can be obtained by merging the data of two lenses, so as to accurately calculate thickness, break through the time resolution limit of single lens;Light path switching is realized using the simple mechanical structure of movable light splitting unit, avoiding the use of extremely expensive high-speed camera, the system cost is low, and the stability is good;Double lens constitutes redundant detection system, if one lens causes image quality to drop due to interference, the data of another lens can still be used as effective reference, improve the reliability of measurement.

Description

Technical Field

[0001] This utility model relates to the field of optical measurement technology, and in particular to a dual-lens system for measuring the depth of printed circuit boards. Background Technology

[0002] Generally, traditional printed circuit board (PCB) depth measurement equipment measures the thickness of exposed copper on a PCB. For example, a depth gauge enters a detection hole, and the exposed copper reflects light transmitted by the gauge. A camera then captures the reflected light. The thickness of the exposed copper is determined by the constant speed of the depth gauge's movement and the duration of the captured light. However, if the actual thickness of the exposed copper is less than the distance the gauge travels within a given time unit, or if the camera's shooting interval is too long, preventing the camera from capturing the complete reflection of the exposed copper, errors will occur in the analysis of the exposed copper's thickness. Therefore, the thickness cannot be accurately determined, thus reducing the effectiveness of the depth measurement equipment. Utility Model Content

[0003] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0004] In view of the problems existing in the prior art, this utility model is proposed.

[0005] Therefore, this utility model aims to solve the technical problem of inaccurate measurement of the thickness of extremely thin copper layers on printed circuit boards.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a dual-lens system for measuring the depth of a printed circuit board, used to measure the detection copper layer in a test hole of a circuit board, comprising: a light source emitter for emitting an incident light; a semi-transparent mirror module disposed on one side of the light source emitter for receiving and reflecting the incident light; a depth measuring device disposed on one side of the semi-transparent mirror module, the depth measuring device being configured to enter the test hole of the circuit board and move towards the semi-transparent mirror module, the depth measuring device being further configured to receive the incident light reflected by the semi-transparent mirror module and incident it onto the detection copper layer, the detection copper layer reflecting the incident light to generate a detection reflected light; and a dual-lens module disposed on the side of the semi-transparent mirror module opposite to the depth measuring device, the dual-lens module comprising a beam splitting unit, a first lens unit and a second lens unit, the first lens unit and the second lens unit being respectively located on both sides of the beam splitting unit; the beam splitting unit being rotatably disposed between the first lens unit and the second lens unit.

[0007] In a preferred embodiment of the dual-lens system for measuring the depth of printed circuit boards according to this utility model, the beam splitting unit is configured such that when the beam splitting unit is tilted relative to the horizontal direction, the beam splitting unit faces the first lens unit, so that the detected reflected light is transmitted to the first lens unit via the beam splitting unit.

[0008] In a preferred embodiment of the dual-lens system for measuring the depth of printed circuit boards according to this utility model, the beam splitting unit is further configured such that when the beam splitting unit is parallel to the horizontal direction, the beam splitting unit faces the second lens unit, so that the detected reflected light is transmitted to the second lens unit via the beam splitting unit.

[0009] As a preferred embodiment of the dual-lens system for measuring the depth of printed circuit boards according to this utility model, the beam splitting unit is a plane mirror or a right-angle prism, and is connected to the housing of the dual-lens module via a rotating shaft.

[0010] In a preferred embodiment of the dual-lens system for measuring the depth of printed circuit boards according to this utility model, the photosensitive surface of the first lens unit and the photosensitive surface of the second lens unit are arranged at an angle, and the rotation axis of the beam splitting unit is located near the bisector of the angle.

[0011] As a preferred embodiment of the dual-lens system for measuring the depth of printed circuit boards according to this utility model, the dual-lens module further includes a light-receiving unit, which is disposed on the optical path of the detected reflected light and located before the beam-splitting unit, and is configured to converge the detected reflected light onto the beam-splitting unit.

[0012] In a preferred embodiment of the dual-lens system for measuring the depth of a printed circuit board according to this utility model, the depth measuring device moves toward the semi-transparent lens module at a constant speed.

[0013] The beneficial effects of this invention are as follows: By alternating sampling in time using dual lenses, even when the copper layer thickness is less than the distance the measuring device moves per unit time, a complete light signal can be obtained by merging the data from the two lenses, thereby accurately calculating the thickness and breaking through the time resolution limitation of a single lens; the optical path switching is achieved using a simple mechanical structure of a movable beam splitter, avoiding the use of an extremely expensive high-speed camera, resulting in low system cost and good stability; the dual lenses constitute a redundant detection system, and if the image quality of one lens deteriorates due to interference, the data from the other lens can still serve as a valid reference, improving the reliability of the measurement. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a perspective view of the present utility model;

[0017] Figure 3 This is a schematic diagram of the optical path when the beam-splitting unit of this utility model is in an inclined position (guiding the optical path to the first lens unit);

[0018] Figure 4 This is a schematic diagram of the optical path when the beam-splitting unit of this utility model is in a horizontal position (guiding the optical path to the second lens unit);

[0019] Figure 5 This is a schematic diagram of the beam splitting unit of this utility model receiving light signals from two lens units under a swing timing.

[0020] Figure 6 This is a schematic diagram of the two lens units receiving light signals under another swing timing of the beam splitting unit of this utility model. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0022] Many specific details are set forth in the following description in order to provide 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 can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Secondly, the term "an embodiment" or "embodiment" as used 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 different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0024] Reference Figures 1 to 4 The dual-lens system 100 for measuring the depth of a printed circuit board is used to measure the detection copper layer 210 in the test hole C of the circuit board. The dual-lens system 100 for measuring the depth of a printed circuit board includes a light source emitter 110, a semi-transparent mirror module 120, a depth measuring device 130, and a dual-lens module 140.

[0025] In some embodiments, a light source emitter 110 emits incident light ray I. A semi-transparent mirror module 120 is disposed on one side of the light source emitter 110 and is used to receive and reflect the incident light ray I. A depth measuring device 130 is disposed on one side of the semi-transparent mirror module 120. The depth measuring device 130 is used to enter the circuit board test hole C and move toward the semi-transparent mirror module 120. For example, the depth measuring device 130 enters the circuit board test hole C at a fixed speed and moves toward the semi-transparent mirror module 120. The depth measuring device 130 receives the incident light ray I reflected by the semi-transparent mirror module 120 and directs the incident light ray I onto the exposed detection copper layer 210 in the circuit board test hole C. The detection copper layer 210 can reflect the incident light ray I to generate a detection reflected light ray L.

[0026] In some embodiments, a dual-lens module 140 is disposed on the side of the translucent mirror module 120 facing away from the depth measuring device 130, and the dual-lens module 140 has a beam splitting unit 142, a first lens unit 144 located on one side of the beam splitting unit 142, and a second lens unit 146 located on the other side of the beam splitting unit 142. According to a key construction of the invention, the beam splitting unit 142 is rotatably disposed between the first lens unit 144 and the second lens unit 146. Specifically, when the beam splitting unit 142 is tilted relative to the horizontal direction D1 (at which time the beam splitting unit 142 faces the first lens unit 144), the detected reflected light L is transmitted to the first lens unit 144 via the beam splitting unit 142, and when the beam splitting unit 142 changes from being tilted relative to the horizontal direction D1 to being parallel to the horizontal direction D1 (at which time the beam splitting unit 142 faces the second lens unit 146), the detected reflected light L is transmitted to the second lens unit 146 via the beam splitting unit 142, so that the first lens unit 144 and the second lens unit 146 receive the detected reflected light L within a unit of time.

[0027] Specifically, the dual-lens module 140 of the printed circuit board depth measurement dual-lens system 100 has a rotatable beam splitter unit 142, which, when tilted relative to the horizontal direction D1 (e.g., ... Figure 3 As shown), the detected reflected light L is transmitted to the first lens unit 144 via the beam splitter 142, and when the beam splitter 142 changes from being tilted relative to the horizontal direction D1 to being parallel to the horizontal direction D1 (as shown), the reflected light L is transmitted to the first lens unit 144. Figure 4 As shown), the detected reflected light L is transmitted to the second lens unit 146 via the beam splitter 142, so that the first lens unit 144 and the second lens unit 146 can completely receive the detected reflected light L within a unit of time. That is, the first lens unit 144 and the second lens unit 146 of the dual-lens module 140 can together completely receive the detected reflected light L within a unit of time. Even if a single lens cannot completely capture the detected reflected light L, it can still be completely captured by the cooperation of the other lens within a unit of time. Therefore, the copper layer thickness H of the detected copper layer 210 can be accurately calculated (see...). Figure 5 This will enhance the application value of the dual-lens system 100 for measuring the depth of printed circuit boards.

[0028] Reference Figures 3 to 6 In some embodiments, the beam-splitting unit 142 of the dual-lens module 140 is further configured to sequentially face the first lens unit 144 and the second lens unit 146 or the second lens unit 146 and the first lens unit 144 within a time unit. In addition, the dual-lens module 140 has a light-receiving unit 148 for detecting reflected light L and transmitting it to the beam-splitting unit 142 via the light-receiving unit 148.

[0029] The dual-lens module 140 is encapsulated within a rigid housing. The detected reflected light L is first collected and converged by the light-collecting unit 148, which is a biconvex converging lens with a focal length of 50 mm. The converged light then enters the beam-splitting unit 142. This beam-splitting unit 142 is a key mechanism for achieving time-division sampling. In a preferred embodiment, it is a high-speed oscillating plane mirror driven by a miniature galvanometer motor. This mirror is mounted within the housing via a rotating shaft, located between the first lens unit 144 and the second lens unit 146. The first lens unit 144 and the second lens unit 146 can be two identical high-frame-rate CMOS industrial cameras, with their optical axes arranged at approximately a 90-degree angle. The rotation axis of the beam-splitting unit 142 is approximately located near the bisector of this angle.

[0030] During system operation, the beam splitter 142 oscillates at high frequency under the control system's commands. Within a preset sampling time unit (e.g., 10 milliseconds), the beam splitter 142 completes one full switching cycle. Figure 3 and Figure 5 In one operating mode shown, at the start of the time interval, the beam splitter tilts at 45 degrees, guiding the light path to the first lens unit 144; at the midpoint of the time interval, it quickly swings to a horizontal position, switching the light path to the second lens unit 146; at the end of the time interval, it returns to the tilted position. It is worth noting that the second lens unit 146 of the dual-lens module 140 captures the detected reflected light L for half the unit time. This means that the second lens unit 146 performs an exposure sampling midway through the time unit. When the detected copper layer 210 is very thin, such that the distance the depth meter 130 moves per unit time is greater than its thickness, this switching mechanism ensures that the first lens unit 144 may capture the first half of the reflected light signal, while the second lens unit 146 captures the second half. Therefore, even if a single lens cannot completely capture the detected reflected light L, the detection reflected light L can still be completely captured by the cooperation of the other lens within the unit time, allowing for accurate calculation of the copper layer thickness of the detected copper layer 210, thereby improving the application value of the dual-lens system 100 for printed circuit board depth measurement.

[0031] Another working mode such as Figure 4 and Figure 6 As shown, the beam splitter 142 starts horizontally, switches to tilt at the midpoint, and returns to horizontal at the end. Its principle is similar to the process described above, achieving complementary temporal sampling between the two lenses. This dual-lens structure based on a rotatable beam splitter cleverly enhances the ability to capture transient light signals through simple mechanical movement, effectively overcoming the time resolution bottleneck of a single lens when measuring extremely thin copper layers, thus significantly improving measurement accuracy and reliability.

[0032] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A dual-lens system for measuring the depth of a printed circuit board, used to measure the detection copper layer (210) in a test hole (C) of a circuit board, characterized in that, include, A light source emitter (110) is used to emit an incident light ray (I); A semi-transparent mirror module (120) is disposed on one side of the light source emitter (110) and is used to receive and reflect the incident light (I). A depth measuring device (130) is disposed on one side of the semi-transparent mirror module (120). The depth measuring device (130) is configured to enter the test hole (C) of the circuit board and move toward the semi-transparent mirror module (120). The depth measuring device (130) is also configured to receive incident light (I) reflected by the semi-transparent mirror module (120) and incident it onto the detection copper layer (210). The detection copper layer (210) reflects the incident light (I) to generate a detection reflected light (L). A dual-lens module (140) is disposed on the side of the semi-transparent mirror module (120) facing away from the depth measuring device (130). The dual-lens module (140) includes a beam splitting unit (142), a first lens unit (144), and a second lens unit (146). The first lens unit (144) and the second lens unit (146) are respectively located on both sides of the beam splitting unit (142). The beam splitting unit (142) is rotatably disposed between the first lens unit (144) and the second lens unit (146).

2. The dual-lens system for measuring depth on printed circuit boards as described in claim 1, characterized in that: The beam splitting unit (142) is configured such that when the beam splitting unit (142) is tilted relative to the horizontal direction (D1), the beam splitting unit (142) faces the first lens unit (144), so that the detected reflected light (L) is transmitted to the first lens unit (144) via the beam splitting unit (142).

3. The dual-lens system for measuring depth on printed circuit boards as described in claim 2, characterized in that: The beam splitting unit (142) is also configured such that when the beam splitting unit (142) is parallel to the horizontal direction (D1), the beam splitting unit (142) faces the second lens unit (146), so that the detected reflected light (L) is transmitted to the second lens unit (146) via the beam splitting unit (142).

4. The dual-lens system for measuring depth on printed circuit boards as described in claim 3, characterized in that: The beam splitting unit (142) is a plane mirror or a right-angle prism, and is connected to the housing of the dual-lens module (140) via a rotating shaft.

5. The dual-lens system for measuring depth on printed circuit boards as described in claim 4, characterized in that: The photosensitive surface of the first lens unit (144) is arranged at an angle to the photosensitive surface of the second lens unit (146), and the rotation axis of the beam splitting unit (142) is located near the bisector of the angle.

6. The dual-lens system for measuring depth on printed circuit boards as described in claim 5, characterized in that: The dual-lens module (140) further includes a light-receiving unit (148), which is disposed in the optical path of the detected reflected light (L) and located in front of the beam-splitting unit (142), and is configured to converge the detected reflected light (L) onto the beam-splitting unit (142).

7. The printed circuit board depth measuring dual lens system of claim 6, wherein: The depth measuring device (130) moves toward the semi-transparent lens module (120) at a constant speed.

Images