Method and device for preparing circuit board with built-in sensor

Abstract

The invention provides a method and a device for preparing a circuit board with a built-in sensor. The method comprises the following steps: acquiring a circuit board substrate; the circuit board substrate is preprocessed according to a preset processing mode, and a preprocessed substrate is obtained; drilling and grooving the pretreated substrate according to preset processing parameters to obtain a first substrate; a hole is formed in the first substrate, grooves are symmetrically formed in the periphery of the wall of the hole, and the groove walls are connected with lateral electrodes; placing a target ball in the hole of the first substrate to obtain a second substrate; laminating a target cover plate with a vertical electrode and the second substrate to obtain a third substrate; when a target ball built in the third substrate is in contact with the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; and carrying out dispensing treatment on the third substrate to obtain a target circuit board. The vibration sensor structure can be arranged in the circuit board, the wiring space is saved, and the size of the whole machine can be reduced.

Description

Technical Field

[0001] This invention relates to the field of circuit board technology, and also to a method and apparatus for manufacturing a circuit board with a built-in sensor. Background Technology

[0002] In consumer electronics, industrial equipment monitoring, security alarms, and smart wearables, miniature multi-directional vibration and attitude sensing sensors are core sensing components. The industry continuously demands increasingly thinner, more integrated, more reliable, lower-cost sensors with no external components. However, traditional vibration sensors are mostly independently packaged devices that need to be soldered onto the PCB (printed circuit board) surface, resulting in significant protrusion and preventing integrated PCB design. This makes them unsuitable for ultra-thin terminal products and occupies additional wiring space, increasing the overall size. Furthermore, traditional PCB manufacturing processes cannot machine high-precision narrow slots in the corners of holes, nor can they create six independent sensing contacts (top, bottom, and four sides) within a single hole, thus hindering the implementation of a PCB-embedded sensor structure. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and apparatus for manufacturing a circuit board with built-in sensors, so as to realize the passive triggering sensing ball of the circuit board, thereby realizing the output of vibration sensing signals with precise sensing in three axes and six directions, and saving wiring space.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A first aspect of the present invention provides a method for fabricating a circuit board with a built-in sensor, comprising: Obtain the circuit board substrate; The circuit board substrate is pre-processed according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning and stress relief. The pre-processed substrate is drilled and grooved according to preset processing parameters to obtain a first substrate; the first substrate has holes, and the holes are symmetrically grooved around the perimeter, with lateral electrodes connected to the groove walls. The target ball is placed into the hole of the first substrate to obtain the second substrate; The target cover plate with the vertical electrode and the second substrate are bonded together to obtain the third substrate; when the target ball inside the third substrate comes into contact with the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal. The third substrate is then subjected to adhesive dispensing to obtain the target circuit board.

[0005] Optionally, the circuit board substrate is pre-processed according to a preset processing method to obtain a pre-processed substrate, including: Obtain a preset processing method; the preset processing method includes leveling, cleaning, and stress relief. The circuit board substrate is preprocessed according to the preset processing method to obtain an initial substrate; The initial substrate is pre-processed and tested to obtain the pre-processing test results; Based on the pretreatment test results and preset compliance conditions, a pretreated substrate is obtained.

[0006] Optionally, the initial substrate is pre-processed and inspected to obtain pre-processing and inspection results, including: according to The substrate flatness error is obtained; where F is the substrate flatness error. The height deviation of the i-th detection point on the initial substrate; according to The contact angle of the substrate surface is obtained; where, denoted as the contact angle of the substrate surface, h as the droplet height, and d as the droplet diameter; The preprocessing detection results are obtained based on the flatness error of the substrate and the contact angle of the substrate surface.

[0007] Optionally, the pre-treated substrate is drilled and grooved according to preset processing parameters to obtain a first substrate, including: Obtain preset processing parameters; the preset processing parameters include preset drilling parameters and preset laser processing parameters; The pre-treated substrate is mechanically drilled according to the preset drilling parameters in the preset processing parameters to obtain a perforated substrate. The perforated substrate is laser-grooved according to the preset laser processing parameters in the preset processing parameters to obtain the first substrate.

[0008] Optionally, the perforated substrate is laser-grooved according to preset laser processing parameters in the preset processing parameters to obtain a first substrate, including: Based on the perforated substrate and the preset groove parameters, the groove processing trajectory is obtained; The perforated substrate is laser etched according to the preset laser processing parameters and the groove processing trajectory to obtain the first substrate.

[0009] Optionally, the target cover plate with vertical electrodes and the second substrate are bonded together to obtain a third substrate, comprising: Obtain the target cover plate with vertical electrodes and preset bonding parameters; The second substrate and the target cover plate with vertical electrodes are bonded together according to the preset bonding parameters to obtain a third substrate; wherein, the side of the target cover plate that is bonded to the second substrate has a vertical electrode; the vertical electrode is circular and its diameter is the same as the diameter of the hole on the second substrate.

[0010] Optionally, obtaining a target cover plate with vertical electrodes includes: Obtain the original cover plate; the original cover plate is an insulating epoxy cover plate; The original cover plate is electroplated according to preset electroplating parameters to obtain a target cover plate with vertical electrodes.

[0011] A second aspect of the present invention provides an apparatus for fabricating a circuit board with a built-in sensor, comprising: The acquisition module is used to acquire the circuit board substrate; A processing module is used to preprocess the circuit board substrate according to a preset processing method to obtain a preprocessed substrate; the preset processing method includes leveling, cleaning, and stress relief; drilling and grooving the preprocessed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes with symmetrical grooves around the hole walls, and each groove wall is connected to a lateral electrode; a target ball is placed into the hole of the first substrate to obtain a second substrate; a target cover plate with a vertical electrode and the second substrate are bonded together to obtain a third substrate; when the target ball inside the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; and adhesive is applied to the third substrate to obtain the target circuit board.

[0012] A third aspect of the present invention provides a computing device, comprising: a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method described in the first aspect.

[0013] A fourth aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method as described in the first aspect.

[0014] The above-described solution of the present invention has at least the following beneficial effects: The above-described solution of the present invention involves obtaining a circuit board substrate; pre-processing the circuit board substrate according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning, and stress relief; drilling and grooving the pre-processed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes with symmetrical grooves around the hole walls, and each groove wall is connected to a lateral electrode; a target ball is placed into the hole of the first substrate to obtain a second substrate; a target cover plate with a vertical electrode and the second substrate are bonded together to obtain a third substrate; when the target ball inside the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; and adhesive is applied to the third substrate to obtain the target circuit board. This solution enables the creation of a vibration sensor structure with built-in, passively triggered, triaxial, six-directional precise sensing, suitable for ultra-thin terminal products. It does not require wiring space, which helps reduce the overall size of the device and improves the adaptability of the circuit board to different scenarios. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of the circuit board fabrication method for the built-in sensor in an embodiment of the present invention; Figure 2 This is a schematic diagram of the circuit board fabrication device with built-in sensors in an embodiment of the present invention. Detailed Implementation

[0016] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0017] like Figure 1 As shown, an embodiment of the present invention proposes a method for fabricating a circuit board with a built-in sensor, comprising the following steps: Step 101: Obtain the circuit board substrate; Step 102: Pre-process the circuit board substrate according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning and stress relief. Step 103: Drill and groove the pre-processed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes and symmetrical grooves around the hole walls, and lateral electrodes are connected to the groove walls. Step 104: Place the target ball into the hole of the first substrate to obtain the second substrate; Step 105: The target cover plate with the vertical electrode and the second substrate are bonded together to obtain the third substrate; when the target ball inside the third substrate comes into contact with the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal. Step 106: Apply adhesive to the third substrate to obtain the target circuit board.

[0018] The method for fabricating a circuit board with a built-in sensor according to an embodiment of the present invention involves: obtaining a circuit board substrate; pre-processing the circuit board substrate according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning, and stress relief; drilling and grooving the pre-processed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes with symmetrical grooves around the hole walls, and each groove wall is connected to a lateral electrode; placing a target ball into the hole of the first substrate to obtain a second substrate; bonding a target cover plate with a vertical electrode to the second substrate to obtain a third substrate; when the target ball embedded in the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; and applying adhesive to the third substrate to obtain the target circuit board. This method enables the creation of a vibration sensor with built-in, passively triggered, triaxial, six-directional precise sensing, suitable for ultra-thin terminal products. It eliminates the need for wiring space, reduces the overall size of the device, and improves the adaptability of the circuit board to different scenarios.

[0019] In an optional embodiment of the present invention, step 101 involves obtaining a circuit board substrate; Specifically, the obtained circuit board substrate can be a standard double-sided or multi-layer FR-4 (a code for flame-retardant material grade) epoxy fiberglass PCB substrate. The substrate has pre-fabricated four sets of lateral electrode lead-out lines (so that the electrodes can be directly exposed after slotting in the holes, allowing the slot walls to connect to the lateral electrodes, enabling the ball bearings to contact the electrodes and generate vibration sensing signals), and signal pads. However, the central sensing area does not have upper and lower electrodes, the surface is not covered with solder mask, and no components are mounted. Depending on the actual situation, other structures or types of circuit board substrates can also be selected; this embodiment does not limit this, and the above is merely an example.

[0020] In an optional embodiment of the present invention, step 102, pre-processing the circuit board substrate according to a preset processing method to obtain a pre-processed substrate, may include: Step 1021: Obtain a preset processing method; the preset processing method includes leveling, cleaning, and stress relief processing; Specifically, the preset processing methods include leveling, cleaning, and stress relief, which can eliminate substrate warping and deformation, internal residual stress, ensure a clean and impurity-free surface, and avoid problems such as misalignment during subsequent processing, failure of sealant bonding, and ball bearing jamming.

[0021] Step 1022: Preprocess the circuit board substrate according to the preset processing method to obtain an initial substrate; Specifically, the substrate is placed in a fully automatic leveling machine, where uniform pressure is applied by upper and lower leveling rollers to correct warping and bending deformation, resulting in a leveled substrate. Then, according to preset stress-relief parameters, the leveled substrate is placed in a constant-temperature annealing furnace for stress relief treatment. Low-temperature holding releases residual internal stress, and the entire process of heating, holding, and cooling is strictly controlled to avoid secondary deformation, resulting in a stress-relieved substrate. Finally, the stress-relieved substrate is ultrasonically cleaned with anhydrous ethanol and deionized water to remove oil, fingerprints, dust, and burrs from its surface. After cleaning, it is dried with hot air to obtain the initial substrate. Here, the preset stress-relief parameters include: through... The obtained holding time and annealing temperature are: The cooling rate should not exceed 2℃ / min, where t is the holding time. The thickness of the flattened substrate.

[0022] Step 1023: Perform pre-processing detection on the initial substrate to obtain the pre-processing detection results; In an optional embodiment of the present invention, step 1023 includes: Step 10231, according to The substrate flatness error is obtained; where F is the substrate flatness error. The height deviation of the i-th detection point on the initial substrate; Specifically, a laser flatness measuring instrument is used to perform non-contact scanning inspection on the initial substrate. Four points at the four corners, four points at the midpoints of the four sides, and one point at the center of the initial substrate are used as detection points, and the Z-axis height deviation data of each point is collected. The flatness error of the substrate is calculated using the above formula.

[0023] Step 10232, according to The contact angle of the substrate surface is obtained; where, denoted as the contact angle of the substrate surface, h as the droplet height, and d as the droplet diameter; Specifically, the surface cleanliness of the initial substrate is detected using a contact angle measuring instrument. High-purity deionized water is then dropped onto the surface of the initial substrate, and the contact angle of the substrate surface is calculated. It should be noted that the droplet height h is the vertical height of the high-purity deionized water droplet after it has formed, referring to the vertical distance (mm) from the highest point of the droplet to the surface of the initial substrate after the deionized water droplet has fallen onto the surface and stabilized. The droplet diameter d is the bottom contact diameter of the droplet, referring to the circular diameter (mm) of the contact surface where the droplet is completely in contact with the surface of the initial substrate, which is measured directly by the vision system of the contact angle measuring instrument by capturing two points on the edge of the droplet contour.

[0024] Step 10233: Obtain the preprocessing detection result based on the substrate flatness error and the substrate surface contact angle.

[0025] Specifically, the pre-processing test results include substrate flatness error and substrate surface contact angle.

[0026] Step 1024: Based on the preprocessing test results and preset compliance conditions, a preprocessed substrate is obtained.

[0027] Specifically, the preset compliance conditions include: the flatness error of the substrate is not greater than 0.02 and the contact angle of the substrate surface is not greater than 15°. If the pretreatment test results match the preset compliance conditions one by one, the pretreated initial substrate can be used as the pretreated substrate for subsequent manufacturing steps. Otherwise, it is necessary to readjust the leveling roller pressure or restart the ultrasonic cleaning process, appropriately increase the cleaning power, extend the cleaning time, and then dry and retest until the pretreatment test results match the preset compliance conditions one by one, so as to ensure that the flatness of the pretreated substrate is qualified and that there are no hydrophobic impurities such as oil and dust on the surface.

[0028] In an optional embodiment of the present invention, step 103, which involves drilling and grooving the pre-treated substrate according to preset processing parameters to obtain a first substrate, may include: Step 1031: Obtain preset processing parameters; the preset processing parameters include preset drilling parameters and preset laser processing parameters; Step 1032: Perform mechanical drilling on the pre-processed substrate according to the preset drilling parameters in the preset processing parameters to obtain a perforated substrate; Step 1033: Perform laser grooving on the perforated substrate according to the preset laser processing parameters in the preset processing parameters to obtain the first substrate.

[0029] Specifically, the preset drilling parameters may include spindle speed, feed rate, retraction rate, and feed method; the preset laser processing parameters may include wavelength, power, spot diameter, and positioning accuracy; after positioning and calibrating the pre-processed substrate, mechanical drilling is performed on the pre-processed substrate according to the preset drilling parameters to process a through-hole with a diameter of 0.75mm, thus obtaining a perforated substrate; positioning grooves are processed at the four corners of the center hole (on the inner wall of the center circular hole, corresponding to the inner wall positions in the four directions of X left, X right, Y front, and Y back) according to the preset laser processing parameters, with a groove width of 0.12 to 0.15mm and a groove depth of 0.53mm, and the insulation resistance between the grooves is not small. At 100MΩ, to eliminate signal crosstalk, it should be noted that the four positioning slots are evenly distributed along the 90° circumference of the central hole and are not interconnected. Each positioning slot has a set of independent lateral separator electrodes (the acquired circuit board substrate has 4 sets of lateral electrode wires embedded inside, with pads leading out from the edge. When slotting, the lateral electrode wires will be exposed to become electrode contact points that contact the ball, i.e., lateral electrodes). The electrodes are tightly attached to the inner wall of the positioning slot, forming four completely independent lateral electrode areas, corresponding to the front, back, left and right horizontal directions respectively. The electrode leads are pre-embedded inside the PCB substrate and extend to the edge of the substrate to lead out signal pins.

[0030] In an optional embodiment of the present invention, step 1033, performing laser grooving on the perforated substrate according to the preset laser processing parameters in the preset processing parameters to obtain a first substrate, includes: Step 10331: Obtain the groove processing trajectory based on the perforated substrate and the preset groove parameters; Step 10332: Perform laser etching on the perforated substrate according to the preset laser processing parameters and the groove processing trajectory in the preset processing parameters to obtain the first substrate.

[0031] Specifically, taking the center O of the central hole on the perforated substrate as the vertex, the 360° circumference is divided into four quadrants, each with an angle domain of 90°. The four slots correspond to the angle bisectors of the first, second, third, and fourth quadrants (45°, 135°, 225°, and 315°), respectively, achieving complete central symmetry. Based on the preset slot width, preset slot length, and center hole radius, the coordinates of the starting point, inflection point, ending point, and rounded corner transition point of a single slot are calculated to generate the trajectory of a single slot. The trajectory of the single slot in the first quadrant is then processed... The groove trajectory is generated by rotating the single groove trajectory around the center O by 90°, 180°, and 270° sequentially, creating a four-way symmetrical groove outline. Rounded corners are applied at the connection points between the grooves and the central hole to remove sharp corners, optimize the laser scanning path, and avoid burrs and substrate carbonization. The symmetry, spacing, and connectivity with the central hole of the four grooves are verified. If the verification is successful, the groove processing trajectory is obtained; otherwise, the trajectory is recalculated based on the center coordinates of the central hole. The perforated substrate is then laser-processed according to preset laser processing parameters and the groove processing trajectory to obtain four positioning grooves evenly distributed along the 90° circumference of the central hole.

[0032] Here, based on the groove width, groove length, and center hole radius, the coordinates of the starting point, inflection point, ending point, and fillet transition point of a single groove are calculated to generate the basic profile. This process includes the following steps: pass , Find the starting point (close to the center) where the inner side of the tank connects to the central hole. pass , Obtain the endpoint of the internal connection of the tank; pass , Obtain the extended end point on the outer side of the tank (left). pass , Obtain the outer extension end point of the tank (right); pass , Obtain the coordinates of the center of the rounded corner; The trajectory of a single tank is obtained based on the coordinates of the starting point connecting the inner side of the tank to the central hole, the ending point connecting the inner side of the tank, the extension endpoint of the outer side of the tank, the extension endpoint of the outer side of the tank, and the center of the rounded corner. in, The coordinates of the starting point where the inner side of the tank connects to the central hole are shown. The coordinates of the endpoint of the connection inside the tank are given. The coordinates of the outer extension endpoint of the tank body. The coordinates of the outer extension endpoint of the tank body. The coordinates of the center of the central hole (the actual center coordinates of the central hole after correction). Here are the coordinates of the fillet center, and R is the radius of the center hole. For the central angle of a single tank, ( radian), The width of the slot is half an angle. (Radian measure), W is the groove width. This is the substrate deflection compensation angle. The radius of the extended tank. L is the outward extension length of the groove, and r is the preset fillet radius (e.g., 0.05mm).

[0033] Here, the trajectory of a single groove is used to define the groove boundary, ensuring accurate groove width and shape. A clockwise closed-loop tool movement is adopted, combining linear interpolation and circular interpolation throughout the entire process to eliminate sharp corners and breakpoints. Taking the starting point connecting the inner side of the groove to the center hole as point A, the ending point connecting the inner side of the groove as point B, the extended endpoint of the outer side of the groove as point C, the extended endpoint of the outer side of the groove as point D, and the coordinates of the rounded corner center as point O1, the trajectory of a single groove is: starting point (laser landing point), point C (outer left endpoint), linear interpolation, point A (inner left starting point), circular interpolation (with O1 as the center and r as the radius, clockwise sweeping to point B), linear interpolation, point D (outer right endpoint), linear interpolation, point C (outer left endpoint), closed-loop tool termination. Here, linear interpolation uses G01 linear interpolation (the standard linear motion command for CNC / laser equipment, also known as linear positioning interpolation command), and the circular transition section uses G02 clockwise circular interpolation (the standard circular motion command, also known as clockwise circular interpolation command). The feed rate is a uniform 800mm / s, without speed changes or pauses, ensuring a smooth contour. This trajectory is completely free of backtracking and breaks, ensuring smooth groove walls, no carbonization, and uniform groove depth.

[0034] In an optional embodiment of the present invention, step 104, inserting the target ball into the hole of the first substrate to obtain the second substrate, may include: Step 1041, according to The target gap is obtained; among which, For the target gap, The aperture of the first substrate is [missing information]. The diameter of the ball bearing; Specifically, the target gap ranges from 0.17 to 0.18 mm. If the gap is too small, it is easy to get stuck, and if the gap is too large, the sensing will be delayed. By using this target gap range, it is easier to screen the preset balls in the future.

[0035] Step 1042, according to The ball bearing roundness error is obtained; where, For ball roundness error, The maximum diameter of the target cross section of the ball. The minimum diameter of the target cross section of the ball; Specifically, the roundness error of the balls is calculated to facilitate the subsequent screening of preset balls.

[0036] Step 1043: Select the preset balls according to the target gap and the ball roundness error to obtain the target balls; Specifically, the target clearance and ball roundness error of the preset balls are calculated. Preset balls with a target clearance within the preset clearance range (e.g., 0.17 to 0.18) and a ball roundness error not exceeding 0.005 are selected as target balls for subsequent manufacturing. Here, the preset balls can be metallic silver balls, achieving advantages such as low wear, no dust pollution, and strong deformation resistance.

[0037] Step 1044: Place the target ball into the hole of the first substrate to obtain the second substrate.

[0038] Specifically, a fully automatic ball-pointing machine can be used to align the target ball with the central hole cavity on the first substrate and accurately place it into the cavity. After placement, the rolling state and static contact state of the ball are detected to ensure that there is no jamming or bias, thus obtaining the second substrate.

[0039] In practical implementation, an automated conveying mechanism can be used to transport the first substrate to the ball bearing assembly station. A vision positioning system identifies the coordinates of the center hole of the first substrate to complete substrate positioning. A fully automated ball bearing machine uses vacuum negative pressure to adsorb a single target ball bearing, with the adsorption force controlled within a range that does not damage the ball bearing or cause it to fall off. The target ball bearing moves above the center hole, and the vision system compares the ball bearing position with the center hole position in real time, performing offset compensation to ensure that the ball bearing and the center hole are coaxial. The ball bearing descends at a uniform speed above the center hole inlet, the vacuum is closed, and the target ball bearing falls precisely into the center hole of the first substrate by gravity. By inserting the ball bearing into the hole of the first substrate, when the ball bearing is subjected to external force, vibration, tilting, or impact, it can contact any one or more of the six contact points to form a conduction signal, achieving independent detection in six directions. This miniaturized sensor structure utilizes the movement of a metal ball bearing within a defined cavity to achieve triaxial, six-directional vibration, tilting, and impact sensing. Four lateral sensing areas + an upper electrode + a lower electrode together constitute six independent sensing contact points.

[0040] In an optional embodiment of the present invention, step 105, obtaining the third substrate based on the second substrate and the target cover plate, may include: Step 1051: Obtain the target cover plate with vertical electrodes and preset bonding parameters; Specifically, preset bonding parameters include bonding pressure (such as 0.3 to 0.5 MPa).

[0041] In an optional embodiment of the present invention, obtaining the target cover plate with the vertical electrode in step 1051 includes: Step 10511: Obtain the original cover plate; the original cover plate is an insulating epoxy cover plate; Specifically, the original cover plate is used to seal the holes on the substrate, prevent the balls from falling out, and achieve a seal. In practice, both ends of a hole are fitted with a cover plate.

[0042] Step 10512: Electroplating the original cover plate according to preset electroplating parameters to obtain a target cover plate with vertical electrodes.

[0043] Specifically, the original cover plate is first cut to obtain the first cover plate, ensuring its dimensions conform to the target dimensions (such as target diameter, length, or width). The first cover plate is then cleaned to obtain the second cover plate. Cleaning removes oil, fingerprints, etc., using a grinding machine at a speed of 1.0 to 1.5 m / m. The second cover plate is then dried to obtain the third cover plate, typically at 80℃ for 10 minutes to ensure a dry surface. Electrode contact patterns are then created on the third cover plate using image transfer. To obtain a cover plate with electrode contact patterns, dry film is applied, exposed, and developed. The cover plate with electrode contact patterns is then electroplated with copper to obtain a first electroplated cover plate. In this step, the cover plate with electrode contact patterns can be pretreated by acid degreasing, micro-etching, dilute sulfuric acid activation, and rinsing with pure water before electroplating. Finally, the electroplated cover plate is electroplated with nickel to obtain a second electroplated cover plate. In this step, the first preset electroplating parameters (including a first preset electroplating solution of nickel sulfamate, a first preset electroplating temperature of 50 to 55°C, and a first preset electroplating current density of 1.0 to...) are followed. The first preset electroplating time is 15 to 25 minutes, and the nickel layer thickness is 3 to 5 mm. The first electroplated cover plate is then electroplated with nickel; after washing the second electroplated cover plate, it is then electroplated with hard gold to obtain the third electroplated cover plate. In this step, the second preset electroplating parameters are followed (including a second preset electroplating solution of gold potassium cobalt cyanide system, a second preset electroplating temperature of 40 to 45°C, and a second preset electroplating current density of 0.3 to...). The second preset electroplating time is 5 to 12 minutes, and the gold layer thickness is 0.1 to 0.3 mm. The electroplated cover plate is electroplated with nickel; based on the third electroplated cover plate, a target cover plate with vertical electrodes is obtained. Here, by removing the film, etching, and stripping the tin from the third electroplated cover plate, an independent electrode is formed to obtain the target cover plate with vertical electrodes.

[0044] In specific implementation, step 10512 can also be replaced by: printing conductive silver paste on the original cover plate according to preset printing parameters to obtain a target cover plate with vertical electrodes.

[0045] Preset printing parameters may include a screen mesh count of 300 to 400 mesh and a wire diameter of 18 to 23 mm. The emulsion thickness (film thickness) is 10 to 15. The opening shape is circular with an opening diameter of 0.75 to 0.85 mm. It also includes: a squeegee angle of 60° to 75°, a printing pressure of 0.15 to 0.3 MPa, a printing speed of 5 to 10 mm / s, a squeegee hardness of 70 to 80° (Shore hardness), and a squeegee-to-cover plate distance of 0.1 to 0.2 mm. It also includes: a low-temperature / medium-temperature curing conductive silver paste, a silver paste viscosity of 15,000 to 25,000 mPa·s, a solid content of 75% to 85%, and a stirring time of 3 to 5 min (before printing).

[0046] In practice, according to the preset printing parameters, a circular conductive silver paste can be screen-printed in the central area of ​​one side of the original cover plate that is attached to the substrate, and then cured at high temperature to form a circular conductive electrode, i.e., a vertical electrode.

[0047] Step 1052: The second substrate and the target cover plate with vertical electrodes are bonded according to the preset bonding parameters to obtain a third substrate; wherein, the side of the target cover plate that is bonded to the second substrate has a vertical electrode; the vertical electrode is circular and its diameter is the same as the diameter of the hole on the second substrate.

[0048] Specifically, a fully automatic laminating machine can be used to precisely align the insulating epoxy cover plate with the upper and lower surfaces of the second substrate, and vacuum adsorb and bond them according to preset bonding parameters to prevent warping or misalignment of the cover plate, thus obtaining a bonded substrate; through The diameters of the upper and lower electrodes were calculated, where, The diameters of the upper and lower electrodes on the electrode substrate. The diameter of the center hole on the electrode substrate is given. Based on the diameters of the upper and lower electrodes, the upper and lower main electrodes are fabricated on the cover plate of the substrate, directly opposite the center hole, using a screen printing silver paste process. The electrodes completely cover the cavity opening, thus obtaining the electrode substrate. The total misalignment deviation of the cover plate was calculated, where, This represents the total misalignment deviation of the cover plate. The coordinates of the center of the cover plate on the electrode substrate are: The center coordinates of the electrode substrate; through The contact resistance between the electrode and the ball was calculated, where, The contact resistance between the electrode and the ball is... For testing voltage (e.g., 5V). To test the current; based on the total misalignment of the cover plate, the contact resistance between the electrode and the ball, and the preset bonding qualification conditions, the third substrate is obtained.

[0049] Here, the preset bonding qualification conditions include: the total deviation of the cover plate alignment is not greater than 0.02 (no misalignment, no warping), and the contact resistance between the electrode and the ball is not greater than 5Ω (no signal crosstalk). If the calculated total deviation of the cover plate alignment and the contact resistance between the electrode and the ball meet the preset bonding qualification conditions, the obtained electrode substrate can be used as the third substrate for subsequent processing.

[0050] In practice, the conductivity and insulation of the electrode substrate can also be tested. If the electrode test results meet the preset electrode qualification standards, it can be used as a third substrate for subsequent processing.

[0051] It should be noted that, in order to prevent the balls from rolling out of the hole, one side of the cover plate can be attached first, the substrate can be flipped over, the balls can fall onto the cover plate, and then the other side of the cover plate can be attached. This is common knowledge to those skilled in the art. Other cover plate attachment methods can also be used according to the actual situation, which will not be listed one by one in this embodiment.

[0052] In an optional embodiment of the present invention, step 106, dispensing adhesive onto the third substrate to obtain the target circuit board, may include: Step 1061: Perform dispensing treatment on the third substrate according to the preset dispensing parameters to obtain a dispensing substrate; Specifically, preset dispensing parameters include dispensing volume, glue line width (e.g., 0.18 to 0.22 mm), glue layer thickness (e.g., 0.04 to 0.06 mm), dispensing speed (e.g., 5 to 8 mm / s), dispensing pressure (e.g., 0.15 to 0.25 MPa), dispensing needle inner diameter (e.g., 0.15 to 0.2 mm), and distance between the dispensing needle and the substrate surface (e.g., 0.2 to 0.3 mm). These can be modified according to actual conditions; the above is only an example. It can be achieved through... The amount of adhesive applied is calculated, where V is the amount of adhesive applied, C is the perimeter of the substrate bonding surface, and W is the width of the adhesive line. This represents the thickness of the adhesive layer.

[0053] Input the preset dispensing parameters into the fully automatic dispensing machine, so that the machine evenly applies insulating epoxy resin adhesive along the seam between the cover plate and the substrate on the third substrate. Strictly control the amount of adhesive to prevent it from seeping into the cavity and contaminating the ball bearings. After dispensing, place the ball bearing in a constant temperature curing oven and cure it according to the preset curing parameters (e.g., curing temperature is...). (Cure time is 30 minutes) After curing, a sealing test and a full-size retest are performed. If the test is qualified, the dispensing substrate is obtained.

[0054] Step 1062: The dispensing substrate is screened according to the preset product qualification conditions to obtain the target circuit board.

[0055] Specifically, through The degree of curing of the adhesive is obtained, wherein, This refers to the degree of curing of the adhesive. To measure the solidification enthalpy change, The standard fully cured enthalpy change (J / g, 350 J / g for epoxy resin); through The pressure leakage rate is obtained, where, For pressure leakage rate, The initial test pressure is negative (-0.05MPa). The pressure (MPa) after holding the pressure for 30 seconds is determined. The adhesive substrate is screened based on the degree of curing of the adhesive, the pressure leakage rate, and the preset product qualification conditions to obtain the target circuit board.

[0056] Here, the preset product qualification conditions include: the glue curing degree qualification condition is not less than 95% (to avoid glue layer cracking, bonding failure, and sealing leakage), and the pressure leakage rate qualification condition is not greater than 0.1% (the cavity is completely sealed, with no air leakage or seepage). If the calculated glue curing degree, pressure leakage rate and preset product qualification conditions are met one by one, then the glued substrate can be used as the target circuit board.

[0057] A specific embodiment of the circuit board fabrication method for the built-in sensor of the present invention includes: Step 111: Obtain the circuit board substrate; The obtained circuit board substrate has four sets of lateral electrode lead-out lines pre-fabricated inside. The central sensing area has no upper and lower electrodes, no green solder mask (solder resist) covering the surface, and no components are mounted.

[0058] Step 112: Pre-process the circuit board substrate according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning and stress relief. The circuit board substrate undergoes pretreatment processes such as leveling, cleaning, and stress relief.

[0059] Step 113: Drill and groove the pre-processed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes and symmetrical grooves around the hole walls, and lateral electrodes are connected to the groove walls. The pre-treated substrate is mechanically drilled and grooves are etched inside the holes using a laser.

[0060] Step 114: Place the target ball into the hole of the first substrate to obtain the second substrate; The 0.4mm metallic silver balls are rounded to remove irregular or broken balls, and the rounded balls are then placed into the substrate.

[0061] Step 115: The target cover plate with the vertical electrode and the second substrate are bonded together to obtain the third substrate; when the target ball inside the third substrate comes into contact with the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal. The insulating epoxy cover plate is precisely aligned with the upper and lower surfaces of the PCB substrate and then bonded together using vacuum adsorption.

[0062] Step 116: Apply adhesive to the third substrate to obtain the target circuit board.

[0063] Insulating epoxy resin is evenly applied along the seam between the cover plate and the substrate to prevent moisture, dust, and oil from entering and ensure the long-term reliability of the sensor.

[0064] The circuit board fabrication method for the built-in sensor of this invention overcomes the shortcomings of existing sensors, such as high cost, large size, and inability to embed sensors in PCBs. The sensor in the circuit board fabricated by this method operates based on the pure physical principle of inertial rolling and electrode contact conduction, without any active driving components, resulting in extremely high reliability. A cavity structure is formed by drilling holes in the substrate and creating symmetrical slots in four directions within the holes. After inserting a ball bearing into the hole, the two empty ends are sealed by upper and lower cover plates. In a static state, the silver ball bearing falls to the bottom of the cavity under gravity, contacting only the lower electrode (vertical electrode) on the lower cover plate, with no inductive signal output. During horizontal (X / Y axis) vibration, the silver ball bearing rolls in the corresponding direction due to inertia, contacting the lateral electrode (lateral electrode on the slot wall), and outputting the corresponding horizontal signal. During vertical (Z axis) vibration, the silver ball bearing bounces up and down, contacting the upper and lower main electrodes, and outputting the vertical signal. During combined vibration, the corresponding electrodes are triggered synchronously, achieving accurate identification in all six directions without blind spots.

[0065] The circuit board fabrication method for the built-in sensor in this invention utilizes a single-hole four-zone structure on a PCB and upper and lower electrodes to form six contacts. A 0.4mm silver bead is placed inside the closed hole. When the sensor vibrates, tilts, moves, or is impacted, the silver bead moves within the hole and contacts the corresponding contact, outputting an independent electrical signal to achieve passive sensing detection in six directions: front, back, left, right, up, and down. It has the following advantages: Six-directional detection in a single hole: Triaxial six-directional independent sensing is achieved within a 0.75mm micro-hole; The sensor is completely built into the circuit board: The sensor is integrated entirely within the circuit board, occupying no additional space and requiring no external components; Passive operation: No power supply, no chip, no circuit drive required; anti-interference, high temperature resistance, and extremely long lifespan; Unique processing technology: Mechanical drilling ensures hole precision, and laser grooving achieves four-zone separation; Extremely low cost: Composed of only a PCB structure and a single silver bead, suitable for mass production at low cost; High sensitivity: The 0.4mm silver bead can respond to weak vibrations, small tilt angles, and slight impacts, resulting in high detection accuracy. The circuit board manufactured by the circuit board preparation method with built-in sensor according to the present invention can be widely used in fields such as micro-motion sensing, tilt detection, vibration alarm, impact detection, posture recognition, smart switch, security equipment, automotive electronics, and small household appliance control.

[0066] like Figure 2 As shown, an embodiment of the present invention provides a circuit board fabrication apparatus 200 with a built-in sensor, comprising: Acquisition module 201 is used to acquire the circuit board substrate; Processing module 202 is used to preprocess the circuit board substrate according to a preset processing method to obtain a preprocessed substrate; the preset processing method includes leveling, cleaning and stress relief; drilling and grooving the preprocessed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes, and the hole walls are symmetrically grooved around the perimeter, with lateral electrodes connected to the groove walls; a target ball is placed into the hole of the first substrate to obtain a second substrate; a target cover plate with a vertical electrode and the second substrate are bonded together to obtain a third substrate; when the target ball inside the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; adhesive is applied to the third substrate to obtain a target circuit board.

[0067] Optionally, the circuit board substrate is pre-processed according to a preset processing method to obtain a pre-processed substrate, including: Obtain a preset processing method; the preset processing method includes leveling, cleaning, and stress relief. The circuit board substrate is preprocessed according to the preset processing method to obtain an initial substrate; The initial substrate is pre-processed and tested to obtain the pre-processing test results; Based on the pretreatment test results and preset compliance conditions, a pretreated substrate is obtained.

[0068] Optionally, the initial substrate is pre-processed and inspected to obtain pre-processing and inspection results, including: according to The substrate flatness error is obtained; where F is the substrate flatness error. The height deviation of the i-th detection point on the initial substrate; according to The contact angle of the substrate surface is obtained; where, denoted as the contact angle of the substrate surface, h as the droplet height, and d as the droplet diameter; The preprocessing detection results are obtained based on the flatness error of the substrate and the contact angle of the substrate surface.

[0069] Optionally, the pre-treated substrate is drilled and grooved according to preset processing parameters to obtain a first substrate, including: Obtain preset processing parameters; the preset processing parameters include preset drilling parameters and preset laser processing parameters; The pre-treated substrate is mechanically drilled according to the preset drilling parameters in the preset processing parameters to obtain a perforated substrate. The perforated substrate is laser-grooved according to the preset laser processing parameters in the preset processing parameters to obtain the first substrate.

[0070] Optionally, the perforated substrate is laser-grooved according to preset laser processing parameters in the preset processing parameters to obtain a first substrate, including: Based on the perforated substrate and the preset groove parameters, the groove processing trajectory is obtained; The perforated substrate is laser etched according to the preset laser processing parameters and the groove processing trajectory to obtain the first substrate.

[0071] Optionally, the target cover plate with vertical electrodes and the second substrate are bonded together to obtain a third substrate, comprising: Obtain the target cover plate with vertical electrodes and preset bonding parameters; The second substrate and the target cover plate with vertical electrodes are bonded together according to the preset bonding parameters to obtain a third substrate; wherein, the side of the target cover plate that is bonded to the second substrate has a vertical electrode; the vertical electrode is circular and its diameter is the same as the diameter of the hole on the second substrate.

[0072] Optionally, obtaining a target cover plate with vertical electrodes includes: Obtain the original cover plate; the original cover plate is an insulating epoxy cover plate; The original cover plate is electroplated according to preset electroplating parameters to obtain a target cover plate with vertical electrodes.

[0073] The circuit board fabrication apparatus for the built-in sensor of this invention involves: acquiring a circuit board substrate; pre-processing the circuit board substrate according to a preset processing method to obtain a pre-processed substrate; the preset processing method includes leveling, cleaning, and stress relief; drilling and grooving the pre-processed substrate according to preset processing parameters to obtain a first substrate; the first substrate has holes with symmetrically grooved walls around the holes, each groove wall connected to a lateral electrode; placing a target ball into the hole of the first substrate to obtain a second substrate; bonding a target cover plate with a vertical electrode to the second substrate to obtain a third substrate; when the target ball embedded in the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; and dispensing adhesive onto the third substrate to obtain the target circuit board. This apparatus enables the creation of a vibration sensor with built-in, passively triggered, triaxial, six-directional precise sensing, suitable for ultra-thin terminal products. It eliminates the need for wiring space, reducing overall device size and improving the circuit board's adaptability to various scenarios.

[0074] It should be noted that this device corresponds to the method described above, and all implementations in the method embodiments described above are applicable to the embodiments of this device and can achieve the same technical effect. Further details are omitted in this embodiment.

[0075] This invention also provides a computing device, including: a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method as described in any of the above embodiments. All implementations in the above method embodiments are applicable to the embodiments of this device and can achieve the same technical effects. Further details are omitted in this embodiment.

[0076] This invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method as described in any of the above embodiments. All implementations in the above method embodiments are applicable to the embodiments of this device and can achieve the same technical effects. Further details are omitted in this embodiment.

[0077] It should be noted that in the apparatus and method of the present invention, the components or steps can obviously be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalent solutions of the present invention. Furthermore, the steps for performing the above series of processes can naturally be performed in the order described and in chronological order, but are not necessarily required to be performed in chronological order. Some steps can be performed in parallel, overlapping, or independently of each other.

[0078] It should be noted that in the above embodiments, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments described above is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0079] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating a circuit board with a built-in sensor, characterized in that, include: Obtain the circuit board substrate; The circuit board substrate is pre-processed according to a preset processing method to obtain a pre-processed substrate. The preset processing methods include leveling, cleaning, and stress relief. The pre-processed substrate is drilled and grooved according to preset processing parameters to obtain a first substrate; the first substrate has holes, and the holes are symmetrically grooved around the perimeter, with lateral electrodes connected to the groove walls. The target ball is placed into the hole of the first substrate to obtain the second substrate; The target cover plate with the vertical electrode and the second substrate are bonded together to obtain the third substrate; when the target ball inside the third substrate comes into contact with the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal. The third substrate is then subjected to adhesive dispensing to obtain the target circuit board.

2. The method for fabricating a circuit board with a built-in sensor according to claim 1, characterized in that, The circuit board substrate is pre-processed according to a preset processing method to obtain a pre-processed substrate, including: Obtain a preset processing method; the preset processing method includes leveling, cleaning, and stress relief. The circuit board substrate is preprocessed according to the preset processing method to obtain an initial substrate; The initial substrate is pre-processed and tested to obtain the pre-processing test results; Based on the pretreatment test results and preset compliance conditions, a pretreated substrate is obtained.

3. The method for fabricating a circuit board with a built-in sensor according to claim 2, characterized in that, The initial substrate is pre-processed and inspected to obtain pre-processing inspection results, including: according to The substrate flatness error is obtained; where F is the substrate flatness error. The height deviation of the i-th detection point on the initial substrate; according to The contact angle of the substrate surface is obtained; where, denoted as the contact angle of the substrate surface, h as the droplet height, and d as the droplet diameter; The preprocessing detection results are obtained based on the flatness error of the substrate and the contact angle of the substrate surface.

4. The method for fabricating a circuit board with a built-in sensor according to claim 1, characterized in that, The pre-treated substrate is drilled and grooved according to preset processing parameters to obtain a first substrate, comprising: Obtain preset processing parameters; the preset processing parameters include preset drilling parameters and preset laser processing parameters; The pre-treated substrate is mechanically drilled according to the preset drilling parameters in the preset processing parameters to obtain a perforated substrate. The perforated substrate is laser-grooved according to the preset laser processing parameters in the preset processing parameters to obtain the first substrate.

5. The method for fabricating a circuit board with a built-in sensor according to claim 4, characterized in that, The perforated substrate is laser-grooved according to the preset laser processing parameters in the preset processing parameters to obtain a first substrate, comprising: Based on the perforated substrate and the preset groove parameters, the groove processing trajectory is obtained; The perforated substrate is laser etched according to the preset laser processing parameters and the groove processing trajectory to obtain the first substrate.

6. The method for fabricating a circuit board with a built-in sensor according to claim 1, characterized in that, A third substrate is obtained by bonding a target cover plate with vertical electrodes and the second substrate together, comprising: Obtain the target cover plate with vertical electrodes and preset bonding parameters; The second substrate and the target cover plate with vertical electrodes are bonded together according to the preset bonding parameters to obtain a third substrate; wherein, the side of the target cover plate that is bonded to the second substrate has a vertical electrode; the vertical electrode is circular and its diameter is the same as the diameter of the hole on the second substrate.

7. The method for fabricating a circuit board with a built-in sensor according to claim 6, characterized in that, Obtaining a target cover plate with vertical electrodes includes: Obtain the original cover plate; the original cover plate is an insulating epoxy cover plate; The original cover plate is electroplated according to preset electroplating parameters to obtain a target cover plate with vertical electrodes.

8. A circuit board fabrication apparatus with a built-in sensor, characterized in that, include: The acquisition module is used to acquire the circuit board substrate; The processing module is used to preprocess the circuit board substrate according to a preset processing method to obtain a preprocessed substrate; The preset processing methods include leveling, cleaning, and stress relief. The pre-processed substrate is drilled and grooved according to preset processing parameters to obtain a first substrate; the first substrate has holes, and the holes are symmetrically grooved around their walls, with lateral electrodes connected to the groove walls; a target ball is placed into the hole of the first substrate to obtain a second substrate; a target cover plate with a vertical electrode and the second substrate are bonded together to obtain a third substrate; when the target ball inside the third substrate contacts the vertical electrode or the lateral electrode, the third substrate generates and outputs a vibration sensing signal; the third substrate is then dispensed with adhesive to obtain a target circuit board.

9. A computing device, characterized in that, include: A processor, a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The system stores instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 7.

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