Drilling device and method for detecting the distance between different conductive layers in a circuit board

Abstract

This invention discloses a drilling device and a method for detecting the spacing between different conductive layers in a circuit board. A drilling module forms an electrical connection with a designated conductive layer, creating a first conductive loop: drilling module – designated conductive layer – conversion module – second power supply. After the height measurement module measures the first height of the designated conductive layer, it switches to the second power supply and connects to an internal reference conductive layer, breaking the first conductive loop. This avoids repeated contact between the drill bit and the designated conductive layer during drilling, which could lead to continuous current signals, easily causing false triggering and misjudgment of the reference point, affecting the subsequent determination of the height of the internal reference conductive layer. During continued drilling, the second height of the internal reference conductive layer can be obtained without changing the drill bit. Thus, the process of detecting the spacing between the surface conductive layer and the internal reference conductive layer can be achieved using a single-sized drill bit, improving detection efficiency and accuracy while reducing tool management costs.

Description

Technical Field

[0001] This invention relates to the field of circuit board manufacturing technology, and in particular to a drilling device and a method for detecting the spacing between different conductive layers in a circuit board. Background Technology

[0002] With the widespread application of electronic products in high-speed signal transmission, the requirements for controlling the length of back-drilled residual stubs on printed circuit boards are becoming increasingly stringent. As the size and dimensions of printed circuit boards increase, the variation in board thickness uniformity also becomes more significant. Therefore, accurately obtaining the actual distance between the inner copper layer and the copper layer on the board surface is a prerequisite for achieving precise depth control processing.

[0003] Current methods for probing back-drilling depth typically involve: first, using a large-diameter drill bit to contact the aluminum sheet to obtain the board height; then, drilling away the surface copper layer; finally, replacing the drill bit with a smaller diameter drill bit and inserting it into the pre-drilled hole to continue drilling until the smaller diameter drill bit contacts the inner probe layer to obtain the inner layer height. This determines the actual thickness from the board surface to the inner probe layer, which is then used for subsequent back-drilling. This method requires frequent switching between different diameter drill bits, making the probing process cumbersome and inefficient. Large-diameter drill bit processing occupies a significant amount of wiring space, which is not conducive to high-density, high-precision circuit layout. Multiple tool changes can introduce cumulative errors, making it difficult to guarantee hole position accuracy and probing accuracy. At the same time, using a combination of large and small-sized tools increases tool procurement, management, and wear costs, making it difficult to meet the requirements for efficient and high-precision back-drilling. Summary of the Invention

[0004] This invention provides a method for detecting the spacing between different conductive layers in a drilling device and a circuit board, so as to improve the efficiency and accuracy of detecting the spacing between different conductive layers in a circuit board and reduce tool management costs.

[0005] According to one aspect of the present invention, a drilling apparatus is provided for drilling a circuit board, the circuit board including a surface conductive layer and an internal reference conductive layer; the drilling apparatus includes: a drilling module, a conversion module, a control module, and a height measurement module; the drilling module is electrically connected to a first pole of a power supply, and the conversion module is electrically connected to a second pole of the power supply; the control module is electrically connected to both the drilling module and the conversion module, and the control module is used to control the conversion module to switch between a set conductive layer being electrically connected to the second pole of the power supply and an internal reference conductive layer being electrically connected to the second pole of the power supply; wherein, the set conductive layer includes a surface conductive layer, or a conductive metal foil disposed on the side of the surface conductive layer away from the internal reference conductive layer; the height measurement module is electrically connected to the control module, and is used to measure the height of the set conductive layer and the height of the internal reference conductive layer during the drilling process of the drilling module, and to upload the measured height to the control module.

[0006] Optionally, the conversion module includes a motor and an actuator. The motor is mechanically connected to the actuator and is also electrically connected to the control module. The motor is used to drive the actuator to switch between a set conductive layer electrically connected to the second pole of the power supply and an internal reference conductive layer electrically connected to the second pole of the power supply, under the control of the control module.

[0007] Optionally, the drilling device further includes a first connecting structure and a second connecting structure, wherein the first connecting structure is electrically connected to a set conductive layer and the second connecting structure is electrically connected to an internal reference conductive layer; the actuator includes a first connecting end and a second connecting end, wherein the first connecting end is electrically connected to the first connecting structure and the second connecting end is electrically connected to the second connecting structure, and the actuator is used to connect the first connecting end to the second pole of the power supply or the second connecting end to the second pole of the power supply under the drive of the motor.

[0008] Optionally, the control module includes a detection unit and a control unit. The detection unit is electrically connected to the control unit. The detection unit is connected in series between the first pole of the power supply and the drilling module, and / or between the conversion module and the second pole of the power supply, for detecting current. The control unit is used to control the conversion module to switch from being electrically connected to one of the set conductive layer and the internal reference conductive layer at the second pole of the power supply to being electrically connected to the other when the current detected by the detection unit is greater than a preset current threshold.

[0009] According to another aspect of the present invention, a method for detecting the spacing between different conductive layers in a circuit board is provided, applicable to a drilling apparatus in any embodiment of the present invention, the detection method comprising: The drilling module is controlled to move towards the circuit board to be processed from the initial state; wherein, in the initial state, the drilling module is located on the set conductive layer of the circuit board to be processed, and the second pole of the power supply is electrically connected to the set conductive layer through the conversion module. When the drilling module and the second pole of the power supply are connected for the first time, the control conversion module switches the second pole of the power supply to be electrically connected to the internal reference conductive layer, and obtains the first height measured by the height measurement module. When the second connection between the drilling module and the second pole of the power supply is obtained for the second time, the second height measured by the height measurement module is obtained; The distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second height and the first height.

[0010] Optionally, upon obtaining the first connection between the drilling module and the second terminal of the power supply, the control conversion module switches the second terminal of the power supply to an electrical connection with the internal reference conductive layer, and obtains the first height measured by the height measurement module, including: Starting from the initial state, when the current between the drilling module and the first terminal of the power supply exceeds the preset current threshold for the first time, or when the current between the conversion module and the second terminal of the power supply exceeds the preset current threshold for the first time, the conversion module is controlled to switch the second terminal of the power supply to the internal reference conductive layer and obtain the first height measured by the height measurement module. Upon obtaining the second connection between the drilling module and the second pole of the power supply, the second height measured by the height measurement module is obtained, including: Starting from the initial state, when the current between the drilling module and the first terminal of the power supply exceeds the preset current threshold for the second time, or when the current between the conversion module and the second terminal of the power supply exceeds the preset current threshold for the second time, the second height measured by the height measurement module is obtained.

[0011] Optionally, upon obtaining the first connection between the drilling module and the second pole of the power supply, the following steps are also included: When the drilling module and the second pole of the power supply are first connected, the first time is recorded and the first time and the first height are stored accordingly. When the second connection between the drilling module and the second pole of the power supply is obtained for the second time, the second time is recorded and stored in correspondence with the second height. Based on the difference between the second height and the first height, the distance between the surface conductive layer and the internal reference conductive layer is determined, including: The distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second height corresponding to the second time and the first height corresponding to the first time.

[0012] Optionally, after confirming the second connection between the drilling module and the second pole of the power supply, the following steps are also included: Return the drilling module to its initial state.

[0013] Optionally, the method for detecting the spacing between different conductive layers in the circuit board further includes: during the process from obtaining the second connection between the drilling module and the second pole of the power supply to the drilling module returning to the initial state, controlling the conversion module to switch the second pole of the power supply to the set conductive layer.

[0014] The circuit board to be processed also includes auxiliary conductive holes, which are electrically connected to the internal reference conductive layer and insulated from the designated conductive layer. Before the drilling module moves from its initial state toward the circuit board to be processed, the method further includes: placing the circuit board to be processed on the machine table of the drilling device and placing a conductive metal foil on the circuit board to be processed; wherein the conductive metal foil includes a cutout window at the position corresponding to the auxiliary conductive hole.

[0015] The drilling device and the method for detecting the spacing between different conductive layers in a circuit board according to embodiments of the present invention use a conversion module, under the control of a control module, to switch between a designated conductive layer electrically connected to the second pole of a power supply and an internal reference conductive layer electrically connected to the second pole of a power supply. During drilling, the drilling module forms a first conductive loop with the designated conductive layer, connecting the first pole of the power supply to the first pole, the drilling module, the designated conductive layer, the conversion module, and the second pole of the power supply. After the height measurement module measures the first height of the designated conductive layer, it switches to electrically connecting the second pole of the power supply to the internal reference conductive layer, cutting off the first conductive loop. This avoids continuous and repeated contact between the drill bit and the designated conductive layer during drilling, which could easily lead to false signal triggering and misjudgment of the reference point, affecting the subsequent determination of the height of the internal reference conductive layer. During the continued drilling process, the second height of the internal reference conductive layer can be obtained without changing the drill bit. Finally, the distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second height and the first height. In this way, the process of detecting the distance between the surface conductive layer and the internal reference conductive layer can be achieved using a drill bit of one size without changing the drill bit, which can improve detection efficiency and accuracy and reduce tool management costs.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a drilling device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a circuit board structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another drilling device provided in an embodiment of the present invention; Figure 4 This is a flowchart of a method for detecting the spacing between different conductive layers in a circuit board, provided by an embodiment of the present invention; Figure 5 This is a flowchart of another method for detecting the spacing between different conductive layers in a circuit board, provided by an embodiment of the present invention; Figure 6This is a schematic diagram showing the conductive layer on the surface of the circuit board to be processed after the conductive metal foil has been placed. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Figure 1 This is a schematic diagram of a drilling device provided in an embodiment of the present invention, for reference. Figure 1 The drilling device is used to drill holes in circuit boards. For example, the drilling device can be a drilling machine with depth control function. Figure 2 This is a schematic diagram of a circuit board structure provided in an embodiment of the present invention, for reference. Figure 2 The circuit board includes a surface conductive layer 10 and an internal reference conductive layer 20. The surface conductive layer 10 includes an upper surface conductive layer 11 and a lower surface conductive layer 12, and the internal reference conductive layer 20 is located between the upper surface conductive layer 11 and the lower surface conductive layer 12. Figure 2As shown, the circuit board also includes a signal layer 40, which optionally is located between the internal reference conductive layer 20 and the lower surface conductive layer 12. The internal reference conductive layer 20 can be additionally provided, or an existing metal conductive layer in the circuit board can be used. For example, preferably, it can be the ground layer or power layer or other signal layer closest to the signal layer 40. That is, the ground layer, power layer or other signal layer that was not originally connected to the auxiliary conductive via 30 can be physically connected to the auxiliary conductive via 30 during circuit board manufacturing, or other signal layers that are already physically connected to the auxiliary conductive via 30 can be directly used as conductive layers. The circuit board also includes an auxiliary conductive via 30, which is electrically connected to the internal reference conductive layer 20 and insulated from the surface conductive layer 10. The auxiliary conductive via 30 can be located in the process edge area of ​​the circuit board, and the signal layer 40 and the auxiliary conductive via 30 are separated by an isolation ring formed by etching a metal layer at the opening of the signal layer 40, and are not conductively connected. A metallized hole ring and an isolation ring are etched at the opening of the auxiliary conductive hole 30 in the surface conductive layer 10 using a mask etching process. The metallized hole ring serves as the auxiliary conductive hole 30, forming a conductive circuit, while the isolation ring isolates the auxiliary conductive hole 30 from the conductive circuit formed between it and the surface conductive layer 10.

[0022] refer to Figure 1 The drilling device includes a drilling module 110, a conversion module 120, a control module 130, and a height measurement module 140. The drilling module 110 is electrically connected to the first terminal A1 of a power supply, and the conversion module 120 is electrically connected to the second terminal A2 of the power supply. The control module 130 is electrically connected to both the drilling module 110 and the conversion module 120, and controls the conversion module 120 to switch between a set conductive layer being electrically connected to the second terminal A2 of the power supply and an internal reference conductive layer 20 being electrically connected to the second terminal A2 of the power supply. The height measurement module 140 is electrically connected to the control module 130 and measures the height of the set conductive layer and the height of the internal reference conductive layer 20 during the drilling process of the drilling module 110, and uploads the measured heights to the control module 130.

[0023] The conductive layer includes a surface conductive layer 10, or a conductive metal foil placed on the side of the surface conductive layer 10 away from the internal reference conductive layer 20. Specifically, the conductive metal foil is placed on the surface conductive layer 10 of the circuit board during drilling to assist the drilling process and to form a flat conductive circuit carrier for the probe. Of the first terminal A1 and the second terminal A2 of the power supply, one is the positive terminal and the other is the negative terminal. For example, the first terminal is positive and the second terminal is negative. The surface conductive layer 10 can be an upper surface conductive layer 11 or a lower surface conductive layer 12; this embodiment of the invention does not specifically limit the specific type.

[0024] The drilling module 110 may include a drill bit drive module, such as a back drill, and includes a spindle. In some embodiments, the drilling module 110 also includes a drill bit. The control module 130 includes a circuit structure with control functions, such as a microcontroller. The control module 130 can control the drilling module 110 to perform drilling on the circuit board. The height measurement module 140 can acquire the height of the conductive layer during the drilling process on the circuit board, for example, by setting the height of the conductive layer and the height of an internal reference conductive layer. The height measurement module 140 includes at least a read head and an optical ruler. Accordingly, for any conductive layer, the height of the conductive layer is the distance between the origin of the main axis in the height direction and the conductive layer.

[0025] In this embodiment of the invention, the drilling device further includes a conversion module 120. The conversion module 120 can electrically connect the set conductive layer to the second terminal A2 of the power supply, or it can electrically connect the internal reference conductive layer 20 to the second terminal A2 of the power supply. For example, by electrically connecting the auxiliary conductive hole 30 to the second terminal A2 of the power supply, the internal reference conductive layer 20 can be electrically connected to the second terminal A2 of the power supply. That is, the conversion module 120 can convert the connection between the second terminal A2 of the power supply and the set conductive layer to the connection between the second terminal A2 of the power supply and the internal reference conductive layer 20, and it can also convert the connection between the second terminal A2 of the power supply and the internal reference conductive layer 20 to the connection between the second terminal A2 of the power supply and the set conductive layer.

[0026] During the drilling process of the drilling module 110, initially, the drilling module 110 is positioned above the designated conductive layer, and the conversion module 120 electrically connects the second terminal A2 of the power supply to the designated conductive layer. As the drilling module 110 gradually moves towards the circuit board, and both the drilling module 110 and the designated conductive layer are electrically connected, a first conductive loop is formed: the first terminal A1 of the power supply - the drilling module 110 - the designated conductive layer - the conversion module 120 - the second terminal A2 of the power supply. The control module 130 can record the first height corresponding to the designated conductive layer at the moment the first conductive loop is formed. Simultaneously, the control module 130 can control the conversion module 120 to switch to a state where the second terminal A2 of the power supply is electrically connected to the internal reference conductive layer 20, thus disconnecting the first conductive loop. When the drilling module 110 is electrically connected to the internal reference conductive layer 20, since the second power supply A2 has been switched to be electrically connected to the internal reference conductive layer 20, a second conductive loop can be formed, consisting of the first power supply A1 - drilling module 110 - internal reference conductive layer 20 - conversion module 120 - second power supply A2. The control module 130 can record the second height of the internal reference conductive layer 20 at the moment the second conductive loop is formed, and then determine the distance between the surface conductive layer 10 and the internal reference conductive layer 20, i.e., the spacing between them, based on the difference between the first height and the second height.

[0027] The drilling device of this invention, under the control of the control module, uses a conversion module to switch between an electrical connection between a set conductive layer and the second pole of the power supply, and an electrical connection between an internal reference conductive layer and the second pole of the power supply. During drilling, the drilling module forms a first conductive loop with the set conductive layer, connecting the first pole of the power supply to the second pole of the power supply. After the height measurement module measures the first height of the set conductive layer, it switches to an electrical connection between the second pole of the power supply and the internal reference conductive layer, cutting off the first conductive loop. This avoids continuous and repeated contact between the drill bit and the set conductive layer during drilling, which could lead to continuous current signal generation, causing false triggering and misjudgment of the reference point, affecting the subsequent determination of the height of the internal reference conductive layer. During continued drilling, the second height of the internal reference conductive layer can be obtained without changing the drill bit. Finally, the distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second and first heights. Thus, the distance between the surface conductive layer and the internal reference conductive layer can be detected using a single-sized drill bit, eliminating the need to change drill bits, improving detection efficiency and accuracy, and reducing tool management costs.

[0028] Figure 3 This is a schematic diagram of another drilling device provided in an embodiment of the present invention. Figure 3 The circuit board is also shown in the reference. Figure 3Optionally, the conversion module 120 includes a motor 121 and an actuator 122. The motor 121 is mechanically connected to the actuator 122, and the motor 121 is also electrically connected to the control module 130. The motor 121 is used to drive the actuator 122 to switch between the electrical connection between the set conductive layer and the second pole A2 of the power supply and the electrical connection between the internal reference conductive layer 20 and the second pole A2 of the power supply under the control of the control module 130.

[0029] In some embodiments, the actuator 122 includes a mechanical switch. Figure 3 The spindle 111 and drill bit 112 of the drilling module 110 are also illustrated by example.

[0030] Specifically, the actuator 122 may include a common terminal B1 and a selection terminal B2. The common terminal B1 can be electrically connected to the second pole A2 of the power supply. The selection terminal B2 of the actuator 122 can be electrically connected to either the set conductive layer or the internal reference conductive layer 20. Driven by the motor 121, the actuator 122 can achieve electrical connection between the selection terminal B2 and either the set conductive layer or the internal reference conductive layer 20. By including the motor 121 and the actuator 122 in the conversion module 120, the conversion speed of the conversion module 120 can be improved, thereby enhancing the speed and accuracy of detecting the distance between the set conductive layer and the internal reference conductive layer 20.

[0031] In some embodiments, the drilling device further includes a first connecting structure 150 and a second connecting structure 160, wherein the first connecting structure 150 is electrically connected to a set conductive layer and the second connecting structure 160 is electrically connected to an internal reference conductive layer 20; the actuator 122 includes a first connecting end B3 and a second connecting end B4, wherein the first connecting end B3 is electrically connected to the first connecting structure 150 and the second connecting end B4 is electrically connected to the second connecting structure 160, and the actuator 122 is used to connect the first connecting end B3 to the second pole A2 of the power supply or the second connecting end B4 to the second pole A2 of the power supply under the drive of the motor 121.

[0032] The first connection structure 150 and the second connection structure 160 can be conductive contacts of a drilling rig. The motor 121 can drive the actuator 122 to electrically connect the selection terminal B2 to the first connection terminal B3, thereby achieving electrical connection between the second pole A2 of the power supply and the set conductive layer; the motor 121 can also drive the actuator 122 to electrically connect the selection terminal B2 to the second connection terminal B4, thereby achieving electrical connection between the second pole A2 of the power supply and the internal reference conductive layer 20, thus realizing the conversion function of the conversion module 120.

[0033] In other embodiments, the conversion module 120 includes an electromagnetic switch, which is not specifically limited in this embodiment of the invention.

[0034] Continue to refer to Figure 3 Optionally, the control module 130 includes a detection unit 131 and a control unit 132. The detection unit 131 is electrically connected to the control unit 132. The detection unit 131 is connected in series between the first terminal A1 of the power supply and the drilling module 110, and / or between the conversion module 120 and the second terminal A2 of the power supply, for detecting current. The control unit 132 is used to control the conversion module 120 to switch from being electrically connected to one of the set conductive layer and the internal reference conductive layer 20, and to being electrically connected to the other, when the current detected by the detection unit 131 is greater than a preset current threshold.

[0035] The detection unit 131 is connected in series in the current conduction circuit of the drilling device. When a first conductive circuit or a second conductive circuit is formed between the first pole A1 and the second pole A2 of the power supply, the current detected by the detection unit 131 will be greater than a preset current threshold. The preset current threshold is greater than or equal to 0. When the current detected by the detection unit 131 is greater than the preset current threshold, the control unit 132 can control the conversion module 120 to switch from electrical connection between the second pole A2 of the power supply and one of the set conductive layer and the internal reference conductive layer 20 to electrical connection with the other.

[0036] For example, as the drilling module 110 gradually moves toward the circuit board, and the drilling module 110 is electrically connected to the set conductive layer and the second pole A2 of the power supply is electrically connected to the set conductive layer, a first conductive loop is formed: the first pole A1 of the power supply - the drilling module 110 - the set conductive layer - the conversion module 120 - the second pole A2 of the power supply. If the current detected by the detection unit 131 is greater than the preset current threshold, the control unit 132 controls the conversion module 120 to switch from the second pole A2 of the power supply being electrically connected to the set conductive layer to the second pole A2 of the power supply being electrically connected to the internal reference conductive layer 20, and at the same time records the first height of the set conductive layer. When the drilling module 110 is electrically connected to the internal reference conductive layer 20, since the second terminal A2 of the power supply has been switched to be electrically connected to the internal reference conductive layer 20, a second conductive loop can be formed: the first terminal A1 of the power supply - the drilling module 110 - the internal reference conductive layer 20 - the conversion module 120 - the second terminal A2 of the power supply. If the current detected by the detection unit 131 is again greater than the preset current threshold, the control unit 132 controls the conversion module 120 to switch from being electrically connected to the internal reference conductive layer 20 via the second terminal A2 of the power supply to being electrically connected to the designated conductive layer, and simultaneously records the second height of the internal reference conductive layer 20. By setting the control module 130 to include the detection unit 131 and the control unit 132, the control unit 132 determines whether a conductive loop has been formed based on the current detected by the detection unit 131. When a conductive loop is formed, the height of the corresponding conductive layer is recorded in a timely manner, and the spacing between different conductive layers can be determined based on the difference in height between different conductive layers.

[0037] This invention also provides a method for detecting the spacing between different conductive layers in a circuit board. Figure 4 This is a flowchart of a method for detecting the spacing between different conductive layers in a circuit board, provided by an embodiment of the present invention. This method is applied to a drilling device and includes the following detection methods: S210, Control the drilling module to move towards the circuit board to be processed from the initial state; wherein, in the initial state, the drilling module is located on the set conductive layer of the circuit board to be processed, and the second pole of the power supply is electrically connected to the set conductive layer through the conversion module.

[0038] Specifically, before drilling, the drilling module is in its initial state, meaning it is positioned above the designated conductive layer of the circuit board to be processed, and no electrical connection is formed between the drilling module and the conductive layer. In this initial state, the second terminal of the power supply is electrically connected to the conductive layer via a conversion module. After drilling is initiated, the drilling module can be controlled to move from its initial state towards the circuit board. Until the drilling module forms an electrical connection with the conductive layer, the conversion module remains stationary, maintaining the connection between the second terminal of the power supply and the conductive layer.

[0039] S220. When the drilling module and the second pole of the power supply are connected for the first time, the control conversion module switches the second pole of the power supply to be electrically connected to the internal reference conductive layer, and obtains the first height measured by the height measurement module.

[0040] Specifically, when the drilling module first connects to the second terminal of the power supply, it indicates that the drilling module has formed an electrical connection with the designated conductive layer. By obtaining the first height measured by the height measurement module at this initial connection, the height of the designated conductive layer can be determined; that is, the first height is the height of the designated conductive layer. Furthermore, by controlling the conversion module to perform a switching action when the initial connection between the drilling module and the second terminal of the power supply is obtained, the state of the power supply's second terminal being electrically connected to the designated conductive layer is switched to the state of the power supply's second terminal being electrically connected to the internal reference conductive layer, thus disconnecting the power supply's second terminal from the designated conductive layer. This prevents the generation of a conductive current signal due to continuous and repeated contact between the drill bit and the designated conductive layer during drilling. In particular, it prevents the drill bit body from continuously contacting the conductive layer during feeding, which could easily lead to signal triggering, misjudgment of the reference point, and affect the determination of the height of the internal reference conductive layer.

[0041] S230. When the second pole of the drilling module and the power supply are connected for the second time, the second height measured by the height measurement module is obtained.

[0042] Specifically, when the drilling module is connected to the second pole of the power supply for the second time, it indicates that the drilling module and the internal reference conductive layer are electrically connected. By obtaining the second height measured by the height measurement module when the drilling module is connected to the second pole of the power supply for the second time, the height of the internal reference conductive layer can be obtained. That is, the second height is the height of the internal reference conductive layer.

[0043] S240. Determine the distance between the surface conductive layer and the internal reference conductive layer based on the difference between the second height and the first height.

[0044] Optionally, when drilling without placing conductive metal foil on the surface conductive layer, the difference between the second height and the first height is determined as the distance between the surface conductive layer and the inner reference conductive layer. When drilling with conductive metal foil on the surface conductive layer, the thickness of the conductive metal foil should also be taken into account; for example, the distance between the surface conductive layer and the inner reference conductive layer can be obtained by subtracting the thickness of the conductive metal foil from the difference between the second height and the first height.

[0045] The method for detecting the spacing between different conductive layers in a circuit board according to this invention involves controlling a drilling module to move towards the circuit board from an initial state. Upon initial connection between the drilling module and the second terminal of the power supply, the first height measured by the height measurement module is used as the height of the set conductive layer. A conversion module is then controlled to switch the electrical connection between the second terminal of the power supply and the internal reference conductive layer. This avoids the continuous generation of a conductive current signal due to repeated contact between the drill bit and the set conductive layer during drilling, which could easily lead to false signal triggering and misjudgment of the reference point, affecting the determination of the height of the internal reference conductive layer. Upon second connection between the drilling module and the second terminal of the power supply, the second height measured by the height measurement module is used as the height of the internal reference conductive layer. Finally, the distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second and first heights. This invention allows for the detection of the spacing between the surface conductive layer and the internal reference conductive layer using a single-sized drill bit, eliminating the need to change drill bits, thus improving detection efficiency and accuracy while reducing tool management costs.

[0046] In some embodiments, S210 includes: starting from an initial state, when the current between the drilling module and the first terminal of the power supply is first greater than a preset current threshold, or when the current between the conversion module and the second terminal of the power supply is first greater than a preset current threshold, controlling the conversion module to switch the second terminal of the power supply to be electrically connected to the internal reference conductive layer, and obtaining the first height measured by the height measurement module.

[0047] Specifically, in the initial state, the conversion module connects the second terminal of the power supply to the set conductive layer. When the drilling module contacts the set conductive layer, a first conductive loop can be formed. Correspondingly, the current in the first conductive loop will be greater than the preset current threshold. By setting a detection unit between the drilling module and the first terminal of the power supply or between the conversion module and the second terminal of the power supply, and based on the current detected by the detection unit, it is determined that the drilling module has contacted the set conductive layer when the detected current is greater than the preset current threshold for the first time since the initial state. This enables the judgment that the drilling module has reached the set conductive layer, and controls the conversion module to switch the second terminal of the power supply to the internal reference conductive layer for electrical connection, and obtains the first height measured by the height measurement module as the height of the set conductive layer.

[0048] The above-mentioned S220 includes: starting from the initial state, when the current between the drilling module and the first pole of the power supply is greater than the preset current threshold for the second time, or when the current between the conversion module and the second pole of the power supply is greater than the preset current threshold for the second time, acquiring the second height measured by the height measurement module.

[0049] Specifically, when the current exceeds the preset current threshold for the first time, the conversion module switches the second terminal of the power supply to be electrically connected to the internal reference conductive layer. When the drilling module contacts the internal reference conductive layer, a second conductive loop can be formed. Correspondingly, the current in the second conductive loop will exceed the preset current threshold. A detection unit can be set between the drilling module and the first terminal of the power supply or between the conversion module and the second terminal of the power supply. Based on the current detected by the detection unit, it can be determined that the drilling module is in contact with the internal reference conductive layer when the detected current exceeds the preset current threshold for the second time, starting from the initial state. This enables the judgment that the drilling module has reached the internal reference conductive layer. When the detected current exceeds the preset current threshold for the second time, the second height measured by the height measurement module is obtained as the height of the internal reference conductive layer.

[0050] In some embodiments, when the drilling module and the second pole of the power supply are first connected, the method further includes: recording a first time and storing the first time and the first height corresponding to the first time and the second time and the second height corresponding to the second time and the second time and the second height corresponding to the second time and the second time and the second height. Accordingly, in the above embodiments, S240 includes determining the distance between the surface conductive layer and the internal reference conductive layer based on the difference between the second height corresponding to the second time and the first height corresponding to the first time.

[0051] Specifically, in this embodiment, when the drilling module and the second pole of the power supply are connected for the first and second time, the first and second times are recorded respectively, and the first time is stored in relation to the first height, and the second time is stored in relation to the second height. When calculating the distance between the surface conductive layer and the internal reference conductive layer, the second height can be found based on the second time, the first height can be found based on the first time, and then the distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the two second heights. This ensures the accuracy of the determined distance between the surface conductive layer and the internal reference conductive layer.

[0052] Figure 5 This is a flowchart of another method for detecting the spacing between different conductive layers in a circuit board, provided by an embodiment of the present invention. (Refer to...) Figure 5 The method for detecting the spacing between different conductive layers in this circuit board includes: S310, Control the drilling module to move towards the circuit board to be processed from the initial state; wherein, in the initial state, the drilling module is located on the set conductive layer of the circuit board to be processed, and the second pole of the power supply is electrically connected to the set conductive layer through the conversion module.

[0053] S320. When the drilling module and the second pole of the power supply are connected for the first time, the control conversion module switches the second pole of the power supply to be electrically connected to the internal reference conductive layer, and obtains the first height measured by the height measurement module.

[0054] S330. When the second pole of the drilling module and the power supply are connected for the second time, the second height measured by the height measurement module is obtained.

[0055] S340. Determine the distance between the surface conductive layer and the internal reference conductive layer based on the difference between the second height and the first height.

[0056] S350, control the drilling module to return to the initial state.

[0057] S350 is executed after the second connection between the drilling module and the power supply is confirmed.

[0058] Specifically, the method for detecting the spacing between different conductive layers in the circuit board of this embodiment can obtain the spacing between the surface conductive layer and different internal reference conductive layers by drilling at multiple points on the circuit board. When drilling at any point, the spacing detection between the surface conductive layer and the internal reference conductive layer can be performed using steps S310 to S340 described above. In some embodiments, in this step, after obtaining the second connection between the drilling module and the second terminal of the power supply, and obtaining the second height measured by the height measurement module, the conversion module is controlled to switch the second terminal of the power supply to the designated conductive layer, allowing drilling to continue until the drilling at that point is completed, at which point a tool return operation is performed. In this step, after the spacing detection and drilling at one point are completed, a tool return operation can be performed, that is, the drilling module is controlled to return to its initial state in preparation for drilling at the next point.

[0059] S360. During the process from obtaining the second connection between the drilling module and the second pole of the power supply to the drilling module returning to the initial state, the control conversion module switches the second pole of the power supply to the set conductive layer for electrical connection.

[0060] After the drilling module connects to the second terminal of the power supply for the second time, if drilling does not continue, the control conversion module can switch from connecting the second terminal of the power supply to the internal reference conductive layer to connecting the second terminal of the power supply to the set conductive layer. This can happen at any time during the process from when the drilling module achieves the second connection to the second terminal of the power supply until it returns to its initial state. This process includes the first moment of achieving the second connection, the second moment of returning to the initial state, and any time between the first and second moments. If drilling continues after the second connection is achieved, once the second connection is achieved and the second height measured by the height measurement module is obtained (i.e., after the drilling module contacts the upper surface of the internal reference conductive layer (the surface of the internal reference conductive layer facing the set conductive layer)), the control conversion module switches the connection between the second terminal of the power supply and the set conductive layer, and then drilling continues until the drilling at that point is complete, followed by a tool return. In this way, after the drilling module returns to its initial state, the second pole of the power supply is electrically connected to the set conductive layer in preparation for drilling at the next point.

[0061] By drilling at multiple points, the spacing between different internal reference conductive layers and surface conductive layers can be obtained, and the spacing between different internal reference conductive layers can be obtained based on the different spacing between the internal reference conductive layers and surface conductive layers.

[0062] refer to Figure 2The circuit board to be processed also includes an auxiliary conductive hole, which is electrically connected to an internal reference conductive layer and insulated from a designated conductive layer. Based on the above-described embodiments, before S210 and S310, the process further includes: placing the circuit board to be processed on the machine table of the drilling device and placing a conductive metal foil on the circuit board to be processed; wherein the conductive metal foil includes a cutout window at the position corresponding to the auxiliary conductive hole.

[0063] Figure 6 This is a schematic diagram showing the conductive layer on the surface of the circuit board to be processed after conductive metal foil has been placed. (Refer to...) Figure 6 Specifically, the conductive metal foil 50, the circuit board to be processed, and the backing plate are placed on the drilling machine's table from top to bottom. During drilling, the drilling module is controlled to move from the side of the conductive metal foil 50 away from the circuit board to the conductive metal foil 50 towards the conductive metal foil 50. The conductive metal foil 50 can be, for example, an aluminum sheet. By placing the conductive metal foil 50 on the circuit board to be processed, a conductive circuit can be formed when the drilling module contacts the conductive metal foil 50 during drilling, thereby obtaining the height of the conductive metal foil 50. The height of the surface conductive layer 10 is then determined based on the height and thickness of the conductive metal foil 50. By setting a perforated window 51 on the conductive metal foil 50, the perforated window 51 exposes the auxiliary conductive hole 30, wherein the area of ​​the perforated window 51 is larger than the area of ​​the auxiliary conductive hole 30, so that the auxiliary conductive hole 30 is insulated from the conductive metal foil 50, so that the conversion module can pass through the perforated window 51 to achieve electrical connection with the auxiliary conductive hole 30, and avoids the conductive metal foil 50 and the auxiliary conductive hole 30 forming a conductive path.

[0064] In the above embodiments of the present invention, the distance between the inner reference conductive layer and the surface conductive layer can be used for subsequent back-drilling. After drilling the through-hole, copper plating is performed to metallize the drilled through-hole. By obtaining the distance between the surface conductive layer and the inner reference conductive layer at the location to be back-drilled, the thickness between the reference conductive layer and the signal layer at the location to be back-drilled is obtained, and its thickness tolerance is proportional to the thickness of the circuit board to be back-drilled. Based on the thickness tolerance between the reference layer and the signal layer, the accuracy tolerance of the back-drilling machine, the drill bit tip compensation value, the copper plating thickness, and the back-drilling residual pile control requirements, the drilling depth is set to complete the back-drilling process.

[0065] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0066] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A drilling device, characterized in that, This device is used to drill holes in a circuit board, which includes a surface conductive layer and an internal reference conductive layer. The drilling apparatus includes a drilling module, a conversion module, a control module, and a height measurement module. The drilling module is electrically connected to the first terminal of a power supply, and the conversion module is electrically connected to the second terminal of the power supply. The control module is electrically connected to the drilling module and the conversion module respectively. The control module is used to control the conversion module to switch between the set conductive layer being electrically connected to the second pole of the power supply and the internal reference conductive layer being electrically connected to the second pole of the power supply. The set conductive layer includes the surface conductive layer or a conductive metal foil placed on the side of the surface conductive layer away from the internal reference conductive layer. The height measurement module is electrically connected to the control module and is used to measure the height of the set conductive layer and the height of the internal reference conductive layer during the drilling process of the drilling module, and upload the measured height to the control module.

2. The drilling apparatus according to claim 1, characterized in that, The conversion module includes a motor and an actuator. The motor is mechanically connected to the actuator and electrically connected to the control module. The motor is used to drive the actuator to switch between the electrical connection between the set conductive layer and the second pole of the power supply and the electrical connection between the internal reference conductive layer and the second pole of the power supply under the control of the control module.

3. The drilling apparatus according to claim 2, characterized in that, It also includes a first connection structure and a second connection structure, the first connection structure being electrically connected to the set conductive layer, and the second connection structure being electrically connected to the internal reference conductive layer; the actuator includes a first connection end and a second connection end, the first connection end being electrically connected to the first connection structure, and the second connection end being electrically connected to the second connection structure, the actuator being used to connect the first connection end to the second pole of the power supply, or to connect the second connection end to the second pole of the power supply, under the drive of the motor.

4. The drilling apparatus according to claim 1, characterized in that, The control module includes a detection unit and a control unit. The detection unit is electrically connected to the control unit. The detection unit is connected in series between the first pole of the power supply and the drilling module, and / or between the conversion module and the second pole of the power supply, for detecting current. The control unit is used to control the conversion module to switch from being electrically connected to one of the power supply's second pole and the set conductive layer and the internal reference conductive layer to being electrically connected to the other when the current detected by the detection unit is greater than a preset current threshold.

5. A method for detecting the spacing between different conductive layers in a circuit board, characterized in that, The detection method, applied to the drilling apparatus according to any one of claims 1-4, comprises: The drilling module is controlled to move towards the circuit board to be processed from an initial state; wherein, in the initial state, the drilling module is located on a set conductive layer of the circuit board to be processed, and the second pole of the power supply is electrically connected to the set conductive layer through the conversion module. When the drilling module is connected to the second pole of the power supply for the first time, the conversion module is controlled to switch the second pole of the power supply to the internal reference conductive layer, and the first height measured by the height measurement module is obtained. When the drilling module is connected to the second pole of the power supply for the second time, the second height measured by the height measurement module is obtained; The distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second height and the first height.

6. The method for detecting the spacing between different conductive layers in a circuit board according to claim 5, characterized in that, Upon initial connection between the drilling module and the second terminal of the power supply, the conversion module is controlled to switch the second terminal of the power supply to the internal reference conductive layer, and the first height measured by the height measurement module is obtained, including: Starting from the initial state, when the current between the drilling module and the first pole of the power supply is greater than the preset current threshold for the first time, or when the current between the conversion module and the second pole of the power supply is greater than the preset current threshold for the first time, the conversion module is controlled to switch the second pole of the power supply to the internal reference conductive layer, and the first height measured by the height measurement module is obtained. When the drilling module is connected to the second pole of the power supply for the second time, the step of obtaining the second height measured by the height measurement module includes: Starting from the initial state, when the current between the drilling module and the first pole of the power supply is greater than the preset current threshold for the second time, or when the current between the conversion module and the second pole of the power supply is greater than the preset current threshold for the second time, the second height measured by the height measurement module is obtained.

7. The method for detecting the spacing between different conductive layers in a circuit board according to claim 5, characterized in that, The step of obtaining the first connection between the drilling module and the second pole of the power supply also includes: When the drilling module is first connected to the second pole of the power supply, the first time is recorded and the first time and the first height are stored accordingly. When the drilling module is connected to the second pole of the power supply for the second time, a second time is recorded and stored in correspondence with the second height. Determining the distance between the surface conductive layer and the internal reference conductive layer based on the difference between the second height and the first height includes: The distance between the surface conductive layer and the internal reference conductive layer is determined based on the difference between the second height corresponding to the second time and the first height corresponding to the first time.

8. The method for detecting the spacing between different conductive layers in a circuit board according to claim 5, characterized in that, After confirming the second connection between the drilling module and the second pole of the power supply, the process further includes: Control the drilling module to return to the initial state.

9. The method for detecting the spacing between different conductive layers in a circuit board according to claim 8, characterized in that, Also includes: During the process from the second connection between the drilling module and the second pole of the power supply to the return of the drilling module to the initial state, the conversion module is controlled to switch the second pole of the power supply to the set conductive layer.

10. The method for detecting the spacing between different conductive layers in a circuit board according to any one of claims 5-9, characterized in that, The circuit board to be processed also includes an auxiliary conductive hole, which is electrically connected to the internal reference conductive layer and insulated from the designated conductive layer; Before controlling the drilling module to move towards the circuit board to be processed from its initial state, the method further includes: The circuit board to be processed is placed on the machine table of the drilling device, and a conductive metal foil is placed on the circuit board to be processed; wherein the conductive metal foil includes a cutout window at the position corresponding to the auxiliary conductive hole.

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