Plate thickness measuring device and plate thickness measuring method

Abstract

The invention belongs to the technical field of PCB production and manufacturing, and discloses a board thickness measuring device and a board thickness measuring method. The plate thickness measuring device comprises a transmission assembly, a sensor assembly and a limiting assembly. The transmission assembly is used for transmitting a PCB, the sensor assembly is installed on the transmission assembly, the sensor assembly comprises a plurality of sensor groups, each sensor group comprises two position sensors, the two position sensors are symmetrically arranged on the upper side and the lower side of the PCB, and the position sensors are configured to be in rolling contact with the PCB. The limiting assembly is installed on the conveying assembly and comprises a plurality of limiting stopper sets, each limiting stopper set comprises two limiting stoppers, the two limiting stoppers are symmetrically arranged on the left side and the right side of the PCB, and the connecting line of the two limiting stoppers is perpendicular to the moving direction of the PCB. According to the plate thickness measuring device, the plate thickness measuring accuracy is improved, manual operation is not needed, and the measuring efficiency is high. The plate thickness measuring method provided by the invention is completed by using the plate thickness measuring device.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB board production and manufacturing, and in particular to a board thickness measuring device and a board thickness measuring method. Background Art

[0002] With the development of high-speed multi-layer PCBs, the thickness of PCBs has gradually increased (thickness > 4mm), and the back drilling depth has also increased accordingly. At the same time, the processing requirements for STUBs have also gradually become higher (2mil-8mil). The increase in board thickness and number of layers has increased the influence of dielectric thickness on board thickness, resulting in poor thickness uniformity of high-speed multi-layer boards and increased thickness range, which poses a great challenge to back drilling deep processing.

[0003] Existing back drilling measurement technologies include partitioned back drilling and drawing back drilling. Partitioned back drilling uses a plate thickness gauge to measure the thickness of each area, and then controls the back drilling depth of each area. However, manual measurement of plate thickness is inefficient, the partition area is large, and the control ability of STUB is insufficient; drawing back drilling can effectively improve the depth control accuracy of back drilling, but measuring plate thickness often leads to waste of 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 technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a plate thickness measuring device and a plate thickness measuring method, aiming to solve the problem that the existing testing device requires manual operation, resulting in low testing efficiency and poor measurement accuracy. The plate thickness measuring device and the 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 object, the present invention adopts the following technical solutions:

[0007] A plate thickness measuring device, comprising:

[0008] Transmission components, used for transmitting PCB boards;

[0009] A sensor assembly is installed on the transmission assembly, the sensor assembly includes a plurality of sensor groups, each of the sensor groups includes 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 be able to roll in contact with the PCB board;

[0010] A limit assembly is installed on the transmission assembly, and the limit assembly includes a plurality of limiter groups, each of which includes two limiters, and the two limiters are symmetrically arranged on the left and right sides of the PCB board, and the connection line of the two limiters is perpendicular to the movement direction of the PCB board.

[0011] In some possible embodiments, each of the sensor groups includes a first state and a second state. When in the first state, the measuring probes of the two position sensors of each sensor group are in contact with each other. When in the second state, the measuring probes of the two position sensors of 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 contact of the measuring probe is configured as a ball structure or a roller structure, and when in the second state, the contact of the measuring probe is in rolling contact with the PCB board.

[0013] In some possible embodiments, signal holes are provided at both ends of the PCB board, a line connecting the two signal holes coincides with a projection of a midline of the PCB board along the direction of movement on a horizontal plane, a line connecting part of the sensor group coincides with a projection of a midline of the PCB board along the direction of movement on a horizontal plane, and a line connecting the contacts of the measuring probes of all the position sensors of the part of the sensor group coincides with a projection of a midline of the PCB board along the direction of movement on a horizontal plane, and when the contacts of the measuring probes of all the position sensors of the part of the sensor group touch the signal holes, the position sensor starts or stops recording data.

[0014] In some possible implementations, the transmission component includes a base and a plurality of transmission rollers that are parallel to each other and rotatably connected to the base, the transmission rollers are used to support the PCB board, and the sensor component and the limit component are both installed on the base.

[0015] In some possible embodiments, the transmission component further includes a plurality of driving members, the plurality of driving members and the plurality of transmission rollers are arranged in one-to-one correspondence, the driving members are mounted on the base and are used to drive the transmission rollers to rotate, and the driving members are arranged as stepping motors.

[0016] In some possible implementations, at least two sensor groups are provided, a connection line of at least two sensor groups is parallel to a movement direction of the PCB board, and intervals between adjacent sensor groups are the same;

[0017] Alternatively, the sensor groups are arranged in multiple columns, each column of the sensor groups includes at least two sensor groups, the connecting lines of all the sensor groups in each column are perpendicular to the movement direction of the PCB board, and the spacing between the sensor groups in adjacent columns is the same.

[0018] The plate thickness measurement method provided by the present invention is performed using the plate thickness measurement device as described in any of the above schemes, and the plate thickness measurement method comprises:

[0019] Providing a PCB board to be measured;

[0020] The PCB board is placed in the transmission assembly and located between two stoppers corresponding to the stopper group;

[0021] The PCB board moves along the transmission component to the sensor component, so that the two position sensors of each sensor group are in rolling contact with the upper and lower surfaces of the PCB board respectively, so as to obtain the board thickness information of the PCB board.

[0022] Beneficial effects of the present invention: In the plate thickness measuring device provided by the present invention, when the PCB moves along the transmission component, two position sensors are symmetrically arranged on the upper and lower sides of the PCB, and the position sensors are in rolling contact with the PCB, so as to continuously measure the plate thickness of the PCB along the thickness direction in real time, which can eliminate the measurement error caused by the warping of the board surface during the traditional plate thickness measurement, improve the accuracy of the plate thickness measurement, and have high measurement efficiency without manual operation; the limit assembly includes a plurality of limiter groups, each of which includes two limiters, and the two limiters are symmetrically arranged on the left and right sides of the PCB, and the connection line of the two limiters is perpendicular to the movement direction of the PCB. The setting of the plurality of limiter groups can effectively ensure the movement stability of the PCB, thereby ensuring the accuracy of the position sensor during measurement, and secondly, can also ensure that the contact position of the position sensor and each PCB is consistent.

[0023] The present invention also provides a board thickness measurement method, which is completed using the above-mentioned board thickness measurement device. The board thickness measurement method effectively improves the accuracy of PCB board thickness measurement, is beneficial to improving the back drilling depth control accuracy, improving processing efficiency, and releasing production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a side view of a PCB board provided by an embodiment of the present invention after being placed in a board thickness measuring device;

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

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

[0027] Figure 4 is a top view of a PCB board provided by an embodiment of the present invention after being placed in a board thickness measuring device;

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

[0029] Figure 6 It is a flow chart of a plate thickness measurement method provided by an embodiment of the present invention.

[0030] In the figure:

[0031] 110, transmission roller; 120, driving member; 210, sensor group; 211, position sensor; 2111, measuring probe; 311, limiter; 400, PCB board; 410, signal hole. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] The present embodiment provides a plate thickness measuring device and a plate thickness measuring method, which aims to solve the problem that the existing test device requires manual operation, resulting in low test efficiency and poor measurement accuracy. The plate thickness measuring device and the 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. This embodiment takes the board to be measured as a PCB board as an example for detailed description. In other embodiments, the board to be measured may also be other types of plates, such as pressed plates, incoming core plates, etc., for monitoring the thickness of incoming plates.

[0037] like Figures 1 to 5 As shown, the plate thickness measuring device includes a transmission component, a sensor component and a limiter component. The transmission component is used to transmit the PCB board 400, the sensor component is installed on the transmission component, the sensor component 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 in contact with the PCB board 400. The limiter component is installed on the transmission component, the limiter component includes a plurality of 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, and the connection line of the two limiters 311 is perpendicular to the movement direction of the PCB board 400. Preferably, the limiter group can be set to three or five, and the three or five limiter groups are arranged at intervals to improve the limit stability. Optionally, the limiter 311 can be set to a plate-like structure or a block-like structure, which can be set as needed.

[0038] In the above-mentioned plate thickness measuring device, when the PCB board 400 moves along the transmission component, the two position sensors 211 are symmetrically arranged on the upper and lower sides of the PCB board 400, and the position sensor 211 is in rolling contact with the PCB board 400, so as to continuously measure the plate thickness of the PCB board 400 along the thickness direction in real time, which can eliminate the measurement error caused by the warping of the board surface during the traditional plate thickness measurement, improve the accuracy of the plate thickness measurement, and do not require manual operation, with high measurement efficiency; the limiter component includes a plurality of limiter groups, each of which includes two limiters 311, and the two limiters 311 are symmetrically arranged on the left and right sides of the PCB board 400, and the connection line of the two limiters 311 is perpendicular to the movement direction of the PCB board 400. The setting of the plurality of limiter groups can effectively ensure the movement stability of the PCB board 400, thereby ensuring the accuracy of the position sensor 211 during measurement, and secondly, it can also ensure that the contact 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 correspondingly 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 up and separated by the PCB board 400 and respectively correspondingly 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 values ​​of their respective contact points relative to the ground, and the difference between the two height values ​​is the board thickness.

[0040] Preferably, the contact of the measuring probe 2111 is configured as a ball structure or a roller structure, and when in the second state, the contact of the measuring probe 2111 is in rolling contact with the PCB board 400. This configuration enables the measuring probe 2111 to continuously measure the thickness of the PCB board 400 when the PCB board 400 moves on the transmission component, while also preventing the board from getting stuck or scratched.

[0041] Optionally, signal holes 410 are provided at both ends of the PCB board 400, and the connecting line of the two signal holes 410 coincides with the projection of the center line of the PCB board 400 along the movement direction on the horizontal plane, the connecting line of the partial sensor group 210 coincides with the projection of the center line of the PCB board 400 along the movement direction on the horizontal plane, and the connecting line of the contacts of the measuring probes 2111 of all the position sensors 211 of the partial sensor group 210 coincides with the projection of the center line of the PCB board 400 along the movement direction on the horizontal plane, and when the contacts of the measuring probes 2111 of all the position sensors 211 of the partial sensor group 210 are in contact with the signal hole 410, the position sensor 211 starts or stops recording data. Taking the first end of the PCB board 400 contacting the transmission component first 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 records 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 is stopped. The projections of the connection line of the two signal holes 410, the center line of the PCB board 400 along the moving direction, and the connection line of the contact points of the measuring probe 2111 of all the position sensors 211 of the partial sensor group 210 on the horizontal plane are all overlapped, that is, the measurement data of the partial position sensor 211 corresponds to the processing thickness data on the center line of the PCB board 400 along the moving direction. At the same time, the stopper group assists in positioning the PCB board, so that the center line of the PCB board 400 along the moving direction always coincides with the projection of the connection line of the contact points of the measuring probe 2111 of all the position sensors 211 of 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, and the size of the signal hole 410 is different from the sizes of other holes in the PCB board 400. For example, the size of the signal hole 410 is larger than the sizes of other holes in the PCB board 400 to avoid recognition errors caused by the measuring probe 2111.

[0042] In this embodiment, see Figure 1 , Figure 1 The arrows in the figure show the transmission direction of the PCB board 400. The transmission component includes a base and a plurality of transmission rollers 110 which are parallel to each other and rotatably connected to the base. The transmission rollers 110 are used to support the PCB board 400. The sensor component and the limit component are both installed on the base. The sensor group 210 is set in the gap between adjacent transmission rollers 110. The transmission rollers 110 transmit the power through rolling friction, with a small friction coefficient and high transmission efficiency. In other embodiments, the transmission component can also be set as a conveyor belt structure, as long as the transmission of the PCB board 400 can be achieved.

[0043] Furthermore, the transmission assembly further includes a plurality of driving members 120, and the plurality of driving members 120 and the plurality of transmission rollers 110 are arranged in a one-to-one correspondence. The driving members 120 are mounted on the base and are used to drive the transmission rollers 110 to rotate. The driving members 120 are arranged as stepper motors. By setting the driving members 120 as stepper motors, in a specific implementation, for example, at least two sensor groups 210 are arranged, and the connection line of 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 a, see Figure 5 PCB board 400 can be set to intermittent displacement, each displacement is a, the pause time is t, the computer reads the board thickness data and matches the pause beat of the synchronous motor to ensure that the spacing of each board thickness measurement is a. In other embodiments, the driving member 120 can also be set as a servo motor, which can be set as needed.

[0044] Or, preferably, see Figure 4 , Figure 4 The middle arrow indicates the transmission direction of the PCB board 400. In order to ensure that sufficient data is obtained along the moving direction of the PCB board 400 and increase the acquisition density of the plate thickness data, the sensor group 210 is arranged in multiple columns, and each column of the sensor group 210 includes at least two sensor groups 210. The connection lines of all sensor groups 210 in each column of the sensor group 210 are perpendicular to the moving direction of the PCB board 400, and the spacing between adjacent sensor groups 210 in each column is the same, which is a, so that the data sampling time of the measuring probe 2111 matches the linear speed of the PCB board 400. This setting makes the data acquisition time of the latter column of sensor groups 210 one step later than the data acquisition of the previous column of sensor groups 210, so as to ensure that the plate thickness data collected in the moving direction of the PCB board 400 is on the same position reference. Exemplarily, the sensor group 210 can be arranged in three or four columns, which can be set as needed. Specifically, the position sensors 211 of each adjacent column of sensor groups 210 can be arranged in parallel or staggered, which can be set as needed. It is easy to imagine that at least two signal holes 410 can be correspondingly set at both ends of the PCB board 400, and the at least two signal holes 410 correspond one-to-one to at least two sensor groups 210 in 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 also includes a data analysis unit, which is electrically connected to the position sensor 211 to obtain board thickness related data, and after analyzing the data, construct a three-dimensional surface diagram between the size of the PCB board 400 (for example, the length of the PCB board 400 is L, and the width is W) and the board thickness of each area of ​​the PCB board 400 (for example, partition data with a spacing of a), so as to grasp the board thickness fluctuation of the PCB board 400, thereby adjusting the corresponding back drilling depth according to the board thickness of each area, so as to achieve the purpose of improving the back drilling accuracy.

[0046] The plate thickness measurement method provided in this embodiment is as follows: Figure 6 As shown, the plate thickness measuring device is used to complete the plate thickness measuring method, which includes the following steps:

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

[0048] S2, placing the PCB board 400 in the transmission assembly and between the two stoppers 311 corresponding to the stopper 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 are in rolling contact with the upper and lower surfaces of the PCB board 400 respectively, so as to obtain the board thickness information of the PCB board 400 .

[0050] The above-mentioned board thickness measurement method effectively improves the accuracy of PCB board 400 board thickness measurement, which is beneficial to improve the back drilling depth control accuracy, improve processing efficiency, and release 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 embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A plate thickness measuring device, characterized in that: include: A transmission component, used for transmitting a PCB board (400); A sensor assembly, mounted on the transmission assembly, the sensor assembly comprising a plurality of sensor groups (210), each of the sensor groups (210) comprising two position sensors (211), the two position sensors (211) being symmetrically arranged on the upper and lower sides of the PCB board (400), and the position sensors (211) being configured to be capable of rolling contact with the PCB board (400); A limit assembly is installed on the transmission assembly, the limit assembly includes a plurality of limiter groups, each of the limiter groups includes two limiters (311), the two limiters (311) are symmetrically arranged on the left and right sides of the PCB board (400), and the connection line of the two limiters (311) is perpendicular to the movement direction of the PCB board (400).

2. The plate thickness measuring device according to claim 1, characterized in that: Each of the sensor groups (210) comprises a first state and a second state. When in the first state, the measuring probes (2111) of the two position sensors (211) of each of the sensor groups (210) are in contact with each other. When in the second state, the measuring probes (2111) of the two position sensors (211) of each of the sensor groups (210) are separated from each other and respectively contact the upper and lower surfaces of the PCB board (400).

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

4. The plate thickness measuring device according to claim 3, characterized in that: Both ends of the PCB (400) are provided with signal holes (410), a line connecting the two signal holes (410) coincides with a projection of the center line of the PCB (400) along the direction of movement on a horizontal plane, a line connecting part of the sensor group (210) coincides with a projection of the center line of the PCB (400) along the direction of movement on a horizontal plane, and a line connecting the contact points of the measuring probes (2111) of all the position sensors (211) of the part of the sensor group (210) coincides with a projection of the center line of the PCB (400) along the direction of movement on a horizontal plane. When the contact points of the measuring probes (2111) of all the position sensors (211) of the sensor group (210) in this part are in contact with the signal hole (410), the position sensor (211) starts or stops recording data, and the stopper group can assist in positioning the PCB board (400) so that the center line of the PCB board (400) along the movement direction always coincides with the projection of the line connecting the contact points of the measuring probes (2111) of all the position sensors (211) of the sensor group (210) in this part on the horizontal plane.

5. The plate thickness measuring device according to claim 1, characterized in that: The transmission component comprises a base and a plurality of transmission rollers (110) which are parallel to each other and rotatably connected to the base, the transmission rollers (110) being used to support the PCB board (400), and the sensor component and the limit component are both mounted on the base.

6. The plate thickness measuring device according to claim 5, characterized in that: The transmission component further comprises a plurality of driving members (120), wherein the plurality of driving members (120) and the plurality of transmission rollers (110) are arranged in a one-to-one correspondence, wherein the driving members (120) are mounted on the base and are used to drive the transmission rollers (110) to rotate, and the driving members (120) are arranged as stepping motors.

7. The plate thickness measuring device according to claim 1, characterized in that: At least two sensor groups (210) are provided, a connection line between 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 groups (210) are arranged in a plurality of columns, each column of the sensor groups (210) includes at least two sensor groups (210), the connection lines of all the sensor groups (210) in each column of the sensor groups (210) are perpendicular to the movement direction of the PCB board (400), and the spacing between the sensor groups (210) in each adjacent column is the same.

8. A plate thickness measurement method, characterized in that: The plate thickness measuring device according to any one of claims 1 to 7 is used to complete the plate thickness measuring method, wherein the plate thickness measuring method comprises: Providing a PCB board (400) to be measured; The PCB board (400) is placed in the transmission component and located between the two stoppers (311) corresponding to the stopper group; The PCB board (400) moves along the transmission component to the sensor component, so that the two position sensors (211) of each sensor group (210) are in rolling contact with the upper and lower surfaces of the PCB board (400) respectively, so as to obtain the board thickness information of the PCB board (400).

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