Plate thickness measuring device and plate thickness measuring method

Abstract

This invention belongs to the field of PCB board manufacturing technology and discloses a board thickness measuring device and method. The board thickness measuring device includes a transmission component, a sensor component, and a limiting component. The transmission component is used to transport the PCB board. The sensor component is mounted on the transmission component and includes several sensor groups. Each sensor group includes two position sensors symmetrically arranged on the upper and lower sides of the PCB board, and the position sensors are configured to roll into contact with the PCB board. The limiting component is mounted on the transmission component and includes several limiter groups. Each limiter group includes two limiters symmetrically arranged on the left and right sides of the PCB board, and the line connecting the two limiters is perpendicular to the direction of movement of the PCB board. The above-described board thickness measuring device improves the accuracy of board thickness measurement, requires no manual operation, and has high measurement efficiency. The board thickness measuring method provided by this invention is performed using the above-described board thickness measuring device.

Description

Technical Field

[0001] This invention relates to the field of PCB manufacturing technology, and in particular to a board thickness measuring device and a board thickness measuring method. Background Technology

[0002] With the development of high-speed multilayer PCBs, PCB thickness is gradually increasing (thickness > 4mm), and back-drilling depth is also increasing accordingly. At the same time, the processing requirements for stumps are also gradually becoming more stringent (2mil-8mil). The increase in board thickness and number of layers makes the influence of dielectric thickness on board thickness greater, resulting in poor thickness uniformity and increased thickness range in high-speed multilayer boards, posing a great challenge to back-drilling depth control processing.

[0003] Existing back-drilling measurement technologies include zone back-drilling and plotting back-drilling. Zone back-drilling uses a plate thickness gauge to measure the plate thickness in each area, thereby controlling the back-drilling depth in each area. However, manual plate thickness measurement is inefficient, the zone area is large, and the control over the STUB is insufficient. Plotting back-drilling can effectively improve the depth control accuracy of back-drilling, but measuring plate thickness often leads to wasted production capacity.

[0004] Therefore, there is an urgent need for a plate thickness measuring device and a plate thickness measuring method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a plate thickness measuring device and a plate thickness measuring method, which aims to solve the problems of low testing efficiency and poor measurement accuracy caused by the need for manual operation of existing testing devices. The plate thickness measuring device and plate thickness measuring method can effectively improve the measurement accuracy, and are conducive to improving the back drilling depth control accuracy, improving processing efficiency, and releasing production capacity.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A plate thickness measuring device, comprising:

[0008] Transmission components are used to transport PCB boards;

[0009] A sensor assembly is mounted on the transmission assembly. The sensor assembly includes several sensor groups, each sensor group including two position sensors. The two position sensors are symmetrically arranged on the upper and lower sides of the PCB board, and the position sensors are configured to make rolling contact with the PCB board.

[0010] A limiting component is installed on the transmission component. The limiting component includes several limiter groups, and each limiter group includes two limiters. The two limiters are symmetrically arranged on the left and right sides of the PCB board, and the line connecting the two limiters is perpendicular to the movement direction of the PCB board.

[0011] In some possible implementations, each of the sensor groups includes a first state and a second state. In the first state, the measuring probes of the two position sensors in each sensor group are in contact with each other. In the second state, the measuring probes of the two position sensors in each sensor group are separated from each other and respectively abut against the upper and lower surfaces of the PCB board.

[0012] In some possible implementations, the contacts of the measuring probe are configured as ball bearings or rollers, and in the second state, the contacts of the measuring probe make rolling contact with the PCB board.

[0013] In some possible implementations, signal holes are provided at both ends of the PCB board. The line connecting the two signal holes coincides with the projection of the centerline of the PCB board along the direction of movement onto the horizontal plane. The line connecting a portion of the sensor group coincides with the projection of the centerline of the PCB board along the direction of movement onto the horizontal plane. Furthermore, the line connecting the contact points of the measuring probes of all the position sensors in this portion of the sensor group coincides with the projection of the centerline of the PCB board along the direction of movement onto the horizontal plane. When the contact points of the measuring probes of all the position sensors in this portion of the sensor group contact the signal holes, the position sensor starts or stops recording data.

[0014] In some possible implementations, the transmission assembly includes a base and a plurality of parallel and rotatably connected drive rollers to the base, the drive rollers being used to support the PCB board, and the sensor assembly and the limiting assembly being mounted on the base.

[0015] In some possible implementations, the transmission assembly further includes a plurality of driving elements, with each driving element and a plurality of transmission rollers corresponding to each other. The driving elements are mounted on the base and are used to drive the transmission rollers to rotate. The driving elements are configured as stepper motors.

[0016] In some possible implementations, the sensor group is provided with at least two, the line connecting the at least two sensor groups is parallel to the direction of movement of the PCB board, and the spacing between adjacent sensor groups is the same;

[0017] Alternatively, the sensor group may be provided in multiple columns, each column of the sensor group including at least two sensor groups, the line connecting all the sensor groups in each column of the sensor group being perpendicular to the direction of movement of the PCB board, and the spacing between adjacent columns of the sensor group being the same.

[0018] The plate thickness measurement method provided by this invention is performed using the plate thickness measurement device described in any of the above embodiments, and the plate thickness measurement method includes:

[0019] Provide a PCB board to be measured;

[0020] The PCB board is placed in the transmission assembly and positioned between the two corresponding limiters of the limiter group;

[0021] The PCB board moves along the transmission assembly to the sensor assembly, so that the two position sensors of each sensor group roll into contact with the upper and lower surfaces of the PCB board to obtain the thickness information of the PCB board.

[0022] The beneficial effects of this invention are as follows: The PCB thickness measuring device provided by this invention has two position sensors symmetrically arranged on the upper and lower sides of the PCB when the PCB moves along the transmission assembly. The position sensors are in rolling contact with the PCB to continuously measure the PCB thickness along the thickness direction in real time. This eliminates measurement errors caused by board warping during traditional thickness measurement, improving the accuracy of thickness measurement. It requires no manual operation and has high measurement efficiency. The limiting assembly includes several limiter groups, each containing two limiters symmetrically arranged on the left and right sides of the PCB. The line connecting the two limiters is perpendicular to the direction of movement of the PCB. The arrangement of several limiter groups effectively ensures the stability of the PCB's movement, thereby ensuring the accuracy of the position sensor measurement. Furthermore, it ensures that the position sensor and each PCB contact position are consistent.

[0023] The present invention also provides a method for measuring board thickness using the aforementioned board thickness measuring device. This method effectively improves the accuracy of PCB board thickness measurement, which is beneficial for improving the precision of back drilling depth control, increasing processing efficiency, and releasing production capacity. Attached Figure Description

[0024] Figure 1 This is a side view of the PCB board placed behind the board thickness measuring device according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the sensor group provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the position sensor in contact with the PCB board according to an embodiment of the present invention;

[0027] Figure 4 This is a top view of the PCB board placed behind the board thickness measuring device according to an embodiment of the present invention;

[0028] Figure 5 This is a time-displacement relationship diagram of the PCB board during movement provided in an embodiment of the present invention;

[0029] Figure 6 This is a flowchart of the plate thickness measurement method provided in an embodiment of the present invention.

[0030] In the picture:

[0031] 110. Drive roller; 120. Drive unit; 210. Sensor group; 211. Position sensor; 2111. Measuring probe; 311. Limit switch; 400. PCB board; 410. Signal hole. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0033] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0036] This embodiment provides a board thickness measurement device and method, aiming to solve the problems of low testing efficiency and poor measurement accuracy caused by the need for manual operation in existing testing devices. The new device and method effectively improve measurement accuracy and enhance back-drilling depth control accuracy, thereby increasing processing efficiency and releasing production capacity. This embodiment uses a PCB board as an example for detailed explanation. In other embodiments, the board to be measured can also be other types of board materials, such as laminated boards, incoming core boards, etc., for monitoring the thickness of incoming boards.

[0037] like Figures 1 to 5 As shown, the board thickness measuring device includes a transmission assembly, a sensor assembly, and a limiting assembly. The transmission assembly is used to transport the PCB board 400. The sensor assembly is mounted on the transmission assembly and includes several sensor groups 210. Each sensor group 210 includes two position sensors 211, which are symmetrically arranged on the upper and lower sides of the PCB board 400 and configured to roll into contact with the PCB board 400. The limiting assembly is mounted on the transmission assembly and includes several limiter groups. Each limiter group includes two limiters 311, which are symmetrically arranged on the left and right sides of the PCB board 400. The line connecting the two limiters 311 is perpendicular to the direction of movement of the PCB board 400. Preferably, three or five limiter groups can be set, with the three or five limiter groups spaced apart to improve limiting stability. Optionally, the limiters 311 can be configured as plate-shaped or block-shaped structures, depending on the needs.

[0038] In the aforementioned board thickness measuring device, when the PCB board 400 moves along the transmission assembly, two position sensors 211 are symmetrically arranged on the upper and lower sides of the PCB board 400, and the position sensors 211 are in rolling contact with the PCB board 400 to continuously measure the thickness of the PCB board 400 in real time along the thickness direction. This can eliminate the measurement error caused by board surface warping in traditional board thickness measurement, improve the accuracy of board thickness measurement, eliminate the need for manual operation, and achieve high measurement efficiency. The limiting assembly includes several limiter groups, each of which includes two limiters 311. The two limiters 311 are symmetrically arranged on the left and right sides of the PCB board 400, and the line connecting the two limiters 311 is perpendicular to the movement direction of the PCB board 400. The arrangement of several limiter groups can effectively ensure the movement stability of the PCB board 400, thereby ensuring the accuracy of the position sensor 211 during measurement. Secondly, it can also ensure that the position of the position sensor 211 and each PCB board 400 is consistent.

[0039] In this embodiment, each sensor group 210 includes a first state and a second state. In the first state, the measuring probes 2111 of the two position sensors 211 of each sensor group 210 are in contact with each other. In the second state, the measuring probes 2111 of the two position sensors 211 of each sensor group 210 are separated from each other and respectively abut against the upper and lower surfaces of the PCB board 400. That is, the measuring probes 2111 of the two position sensors 211 are set to passive measurement. When not working, the measuring probes 2111 of the two position sensors 211 of each sensor group 210 are in contact with each other. When the PCB board 400 is placed in the transmission assembly and transported, the measuring probes 2111 of the two position sensors 211 of each sensor group 210 are lifted and separated by the PCB board 400 and respectively abut against the upper and lower surfaces of the PCB board 400. At this time, the two position sensors 211 respectively obtain the position information of the upper and lower surfaces of the PCB board 400. For example, the measuring probes 2111 of the two position sensors 211 respectively obtain the height value of their respective contact points relative to the ground, and the difference between the two height values ​​is the board thickness.

[0040] Preferably, the contacts of the measuring probe 2111 are configured as ball bearings or rollers, and in the second state, the contacts of the measuring probe 2111 roll into contact with the PCB board 400. This configuration allows the measuring probe 2111 to continuously measure the thickness of the PCB board 400 while it moves on the transmission assembly, while also preventing jamming or scratching of the board surface.

[0041] Optionally, signal holes 410 are provided at both ends of the PCB board 400. The line connecting the two signal holes 410 coincides with the projection of the center line of the PCB board 400 along the direction of movement onto the horizontal plane. The line connecting a portion of the sensor group 210 coincides with the projection of the center line of the PCB board 400 along the direction of movement onto the horizontal plane. Furthermore, the line connecting the contact points of the measuring probes 2111 of all the position sensors 211 in this portion of the sensor group 210 coincides with the projection of the center line of the PCB board 400 along the direction of movement onto the horizontal plane. When the contact points of the measuring probes 2111 of all the position sensors 211 in this portion of the sensor group 210 contact the signal holes 410, the position sensors 211 start or stop recording data. Taking the first end of the PCB board 400 contacting the transmission component as an example, when the measuring probe 2111 passes through the signal hole 410 at the first end of the PCB board 400, the measuring probe 2111 will generate signal fluctuations, and the computer background will record the board thickness data at this time. When the measuring probe 2111 passes through the signal hole 410 at the second end of the PCB board 400, the recording of the board thickness data will stop. The projections of the lines connecting the two signal holes 410, the centerline of the PCB board 400 along the direction of movement, and the lines connecting the contact points of the measuring probes 2111 of all position sensors 211 in the partial sensor group 210 on the horizontal plane all coincide. That is, the measurement data of this partial position sensor 211 corresponds to the processing thickness data on the centerline of the PCB board 400 along the direction of movement. At the same time, the limiter group assists in positioning the PCB board, so that the centerline of the PCB board 400 along the direction of movement always coincides with the projection of the lines connecting the contact points of the measuring probes 2111 of all position sensors 211 in the partial sensor group 210 on the horizontal plane, ensuring the accuracy of measurement and data correspondence. It is easy to imagine that the size of the signal hole 410 is smaller than the size of the contact of the measuring probe 2111 and smaller than the size of the measuring probe 2111. Furthermore, the size of the signal hole 410 is different from the size of other holes on the PCB board 400. For example, the size of the signal hole 410 is larger than the size of other holes on the PCB board 400, in order to avoid the measuring probe 2111 from generating recognition errors.

[0042] In this embodiment, see Figure 1 , Figure 1 Arrows indicate the transmission direction of the PCB board 400. The transmission assembly includes a base and multiple parallel and rotatably connected drive rollers 110. The drive rollers 110 support the PCB board 400. Sensor assemblies and limiting assemblies are mounted on the base, and sensor groups 210 are positioned in the gaps between adjacent drive rollers 110. The drive rollers 110 transmit power through rolling friction, resulting in a low coefficient of friction and high transmission efficiency. In other embodiments, the transmission assembly can also be configured as a conveyor belt structure, as long as it enables the transmission of the PCB board 400.

[0043] Furthermore, the transmission assembly also includes multiple driving components 120, each corresponding to a multiple transmission roller 110. The driving components 120 are mounted on the base and used to drive the transmission rollers 110 to rotate. Each driving component 120 is configured as a stepper motor. By configuring the driving component 120 as a stepper motor, in specific implementations, for example, at least two sensor groups 210 are provided. The connection line between at least two sensor groups 210 is parallel to the direction of movement of the PCB board 400, and the spacing between adjacent sensor groups 210 is always 'a'. (See [reference]). Figure 5 The PCB board 400 can be configured for intermittent displacement, with each displacement segment being 'a' and a pause time being 't'. The computer reads the board thickness data, and the pause time of the synchronous motor matches the timing, ensuring that the interval for each board thickness measurement is 'a'. In other embodiments, the drive unit 120 can also be configured as a servo motor, which can be set as needed.

[0044] Alternatively, preferably, see Figure 4 , Figure 4 The middle arrow indicates the transmission direction of the PCB board 400. To ensure sufficient data acquisition along the movement direction of the PCB board 400 and increase the acquisition density of board thickness data, the sensor group 210 is configured with multiple columns. Each column of sensor group 210 includes at least two sensor groups 210. The connecting lines of all sensor groups 210 in each column are perpendicular to the movement direction of the PCB board 400, and the spacing between adjacent columns of sensor groups 210 is the same, 'a'. This ensures that the data sampling time of the measuring probe 2111 matches the linear velocity of the PCB board 400. This configuration ensures that the data acquisition time of the subsequent column of sensor groups 210 is one step later than that of the previous column, thus guaranteeing that the board thickness data acquired along the movement direction of the PCB board 400 is at the same position reference. For example, the sensor group 210 can be configured with three or four columns, as needed. Specifically, the position sensors 211 of adjacent columns of sensor groups 210 can be arranged in parallel or staggered, as needed. It is easy to imagine that at least two signal holes 410 can be provided at both ends of the PCB board 400, and at least two signal holes 410 correspond one-to-one with at least two sensor groups 210 of each column of sensor groups 210, so that the measurement data of the position sensor 211 corresponds to the processing thickness of the corresponding position of the PCB board 400.

[0045] In this embodiment, the board thickness measuring device further includes a data analysis unit, which is electrically connected to the position sensor 211 to acquire board thickness-related data. After analyzing the data, the data analysis unit constructs a three-dimensional surface map between the dimensions of the PCB board 400 (e.g., the length of the PCB board 400 is L and the width is W) and the board thickness of each region of the PCB board 400 (e.g., partition data with a spacing of a), thereby understanding the board thickness fluctuation of the PCB board 400 and adjusting the corresponding back drilling depth according to the board thickness of each region to improve the back drilling accuracy.

[0046] The plate thickness measurement method provided in this embodiment is as follows: Figure 6 As shown, the plate thickness measurement is performed using the aforementioned plate thickness measuring device. The plate thickness measurement method includes the following steps:

[0047] S1. Provide a PCB board 400 to be measured;

[0048] S2. Place the PCB board 400 in the transmission assembly and between the two limiters 311 corresponding to the limiter group;

[0049] S3. The PCB board 400 moves along the transmission assembly to the sensor assembly, so that the two position sensors 211 of each sensor group 210 roll into contact with the upper and lower surfaces of the PCB board 400 respectively, so as to obtain the thickness information of the PCB board 400.

[0050] The above-mentioned board thickness measurement method effectively improves the accuracy of PCB board thickness measurement of 400mm, which is conducive to improving the depth control accuracy of back drilling, increasing processing efficiency, and releasing production capacity.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A plate thickness measuring device, characterized in that, include: Transmission component for transmitting PCB board (400); A sensor assembly is installed on the transmission assembly. The sensor assembly includes a plurality of sensor groups (210). Each sensor group (210) includes two position sensors (211). The two position sensors (211) are symmetrically arranged on the upper and lower sides of the PCB board (400), and the position sensors (211) are configured to be able to roll contact with the PCB board (400). A limiting component is installed on the transmission component. The limiting component includes several limiter groups. Each limiter group includes two limiters (311). The two limiters (311) are symmetrically arranged on the left and right sides of the PCB board (400). The line connecting the two limiters (311) is perpendicular to the movement direction of the PCB board (400). Each of the sensor groups (210) includes a first state and a second state. In the first state, the measuring probes (2111) of the two position sensors (211) of each sensor group (210) are in contact with each other. In the second state, the measuring probes (2111) of the two position sensors (211) of each sensor group (210) are separated from each other and respectively abut against the upper and lower surfaces of the PCB board (400). Signal holes (410) are provided at both ends of the PCB board (400). The line connecting the two signal holes (410) coincides with the projection of the centerline of the PCB board (400) along the direction of movement onto the horizontal plane. The line connecting a portion of the sensor group (210) coincides with the projection of the centerline of the PCB board (400) along the direction of movement onto the horizontal plane. Furthermore, the line connecting the contact points of the measuring probes (2111) of all the position sensors (211) of this portion of the sensor group (210) coincides with the projection of the centerline of the PCB board (400) along the direction of movement onto the horizontal plane. When the contact points of the measuring probes (2111) of all the position sensors (211) in this part of the sensor group (210) are in contact with the signal hole (410), the position sensors (211) start or stop recording data, and the limiter group can assist in positioning the PCB board (400) so that the centerline of the PCB board (400) along the direction of movement always coincides with the projection of the line connecting the contact points of the measuring probes (2111) of all the position sensors (211) in this part of the sensor group (210) on the horizontal plane.

2. The plate thickness measuring device according to claim 1, characterized in that, The contact of the measuring probe (2111) is configured as a ball bearing structure or a roller structure. When in the second state, the contact of the measuring probe (2111) makes rolling contact with the PCB board (400).

3. The plate thickness measuring device according to claim 1, characterized in that, The transmission component includes a base and a plurality of parallel and rotatably connected transmission rollers (110) to the base. The transmission rollers (110) are used to support the PCB board (400). The sensor component and the limiting component are both mounted on the base.

4. The plate thickness measuring device according to claim 3, characterized in that, The transmission component further includes multiple driving elements (120), and the multiple driving elements (120) and the multiple transmission rollers (110) are arranged in a one-to-one correspondence. The driving elements (120) are mounted on the base and are used to drive the transmission rollers (110) to rotate. The driving elements (120) are configured as stepper motors.

5. The plate thickness measuring device according to claim 1, characterized in that, The sensor group (210) is provided in at least two, and the line connecting the at least two sensor groups (210) is parallel to the movement direction of the PCB board (400), and the spacing between adjacent sensor groups (210) is the same. Alternatively, the sensor group (210) may be provided in multiple columns, each column of the sensor group (210) may include at least two sensor groups (210), the line connecting all the sensor groups (210) in each column of the sensor group (210) may be perpendicular to the direction of movement of the PCB board (400), and the spacing between adjacent columns of the sensor group (210) may be the same.

6. A method for measuring plate thickness, characterized in that, The plate thickness measurement method is performed using the plate thickness measuring device as described in any one of claims 1-5, and includes: Provide a PCB board (400) to be measured; The PCB board (400) is placed in the transmission assembly and positioned between the two limiters (311) corresponding to the limiter group; The PCB board (400) moves along the transmission assembly to the sensor assembly, so that the two position sensors (211) of each sensor group (210) roll into contact with the upper and lower surfaces of the PCB board (400) respectively to obtain the thickness information of the PCB board (400).

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