Grinding device for improving orifice burrs

Abstract

The utility model relates to a grinding device for improving orifice burrs, which belongs to the technical field of PCB (printed circuit board) manufacturing and comprises a frame, a roller conveying belt and a first motor are arranged on the frame, a polish-brush wheel set is embedded in the roller conveying belt, a second motor is mounted on the frame, and the polish-brush wheel set comprises a support, a polish-brush shaft, an upper polish-brush wheel and a lower polish-brush wheel. The polish-brush shafts are arranged on the rack through a support and embedded into the roller conveying belt, the upper polish-brush shaft is provided with an upper polish-brush wheel, and the lower polish-brush shaft is provided with a lower polish-brush wheel; the three polish-brush wheel sets comprise the first polish-brush wheel set, the second polish-brush wheel set and the third polish-brush wheel set, abrasive belt layers are arranged on the outer surfaces of an upper polish-brush wheel and a lower polish-brush wheel in the first polish-brush wheel set, and ceramic layers are arranged on the outer surfaces of an upper polish-brush wheel and a lower polish-brush wheel in the second polish-brush wheel set. Non-woven fabric layers are arranged on the outer surfaces of the upper polish-brush wheel and the lower polish-brush wheel in the third polish-brush wheel set; the grinding device is simple in structure and convenient to use, the grinding yield can be effectively increased, and the occurrence of small and abnormal burr holes caused by grinding is reduced.

Description

Technical Field

[0001] The utility model relates to a grinding device, in particular to a grinding device for improving burrs at the hole opening, belonging to the technical field of PCB board manufacturing. Background Technique

[0002] After drilling the existing PCB board, sandpaper grinding + needle brush grinding are used to grind the burrs, and then ultrasonic immersion washing and high-pressure water washing are used to clean the residual copper foreign matters at the hole opening and hole wall.

[0003] The mesh numbers of the sandpaper and brush wheel range from 320 to 600, and each company selects different grinding brushes according to the order structure and process, which solves more than 80% of the burr and burr problems at the hole opening, but there are still some problems.

[0004] Currently, in the patent CN204604032U, a printing circuit board grinding brush device, this grinding device places the circuit board that needs to grind the burrs of the drilled hole on the roller conveyor belt between the grinding brush wheel and the steel roller, controls the rotation of the roller conveyor belt and the grinding brush wheel, and uses the abrasive belt set on the grinding brush wheel to grind the burrs of the circuit board. The ground circuit board is connected and transmitted to the next process through the lifting device. The utility model greatly reduces the labor intensity of employees and the production cost of products, and can be organically combined with the ordinary circuit board production line, with general usability. Only the abrasive belt is used for grinding in this device, the cutting at the hole opening is less, and at the same time, the cutting uniformity of the board surface is easily affected, which will lead to burrs at the hole opening after grinding the protrusion at the hole opening after drilling and electroplating, resulting in abnormal small holes, and problems such as leakage and outflow of abnormal small holes in some press-fit holes and test holes.

[0005] Therefore, researching and developing a grinding device for improving burrs at the hole opening that can overcome the above defects has become an urgent technical problem for those skilled in the art. Content of the Utility Model

[0006] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and provide a grinding device for improving burrs at the hole opening. The grinding device has a simple structure and is convenient to use, can effectively improve the grinding yield, and reduce the generation of abnormal burr holes and small holes caused by grinding.

[0007] To solve the above technical problems, the utility model provides a grinding device for improving burrs at the hole opening, including a frame, on which a roller conveyor belt for conveying the PCB board is provided, and a first motor connected to and driving the roller conveyor belt to work. A grinding brush wheel set is embedded in the roller conveyor belt, and a second motor connected to and driving the grinding brush wheel set to rotate is installed on the frame. The PCB board is conveyed to the grinding brush wheel set by the roller conveyor belt for grinding;

[0008] The grinding brush wheel set includes a bracket, a grinding brush shaft, an upper grinding brush wheel and a lower grinding brush wheel. Two grinding brush shafts are arranged parallel to each other up and down. The grinding brush shafts are arranged on the frame through the bracket and embedded in the roller conveyor belt. The upper grinding brush wheel is arranged on the upper grinding brush shaft, and the lower grinding brush wheel is arranged on the lower grinding brush shaft. A space for the PCB board to pass through is left between the upper grinding brush wheel and the lower grinding brush wheel;

[0009] There are three sets of grinding brush wheel sets, including a first grinding brush wheel set, a second grinding brush wheel set and a third grinding brush wheel set arranged in parallel at intervals. On the outer surfaces of the upper grinding brush wheel and the lower grinding brush wheel in the first grinding brush wheel set, there is an abrasive belt layer for grinding. On the outer surfaces of the upper grinding brush wheel and the lower grinding brush wheel in the second grinding brush wheel set, there is a ceramic layer for grinding. On the outer surfaces of the upper grinding brush wheel and the lower grinding brush wheel in the third grinding brush wheel set, there is a non-woven fabric layer for grinding.

[0010] The further limited technical solution of the present utility model is:

[0011] Further, in the aforementioned grinding device for improving the burr at the hole opening, the non-woven fabric in the non-woven fabric layer is a radial 600-mesh non-woven fabric.

[0012] Technical effect: Currently, the generally used non-woven fabric grinding is 600-mesh dry-rolled non-woven fabric. The rolled structure is a product formed by winding non-woven fabric materials around a bakelite tube and impregnating with glue. Its characteristics are large grinding force, high hardness (less damage to the hole opening), fast abrasive shedding, good self-sharpening property, high grinding efficiency. When contacting the PCB board surface, it is a single-line contact, the abrasive grains are concentrated and uniform, and the grinding is uniform. It is suitable for processes such as grinding the resin of the PCB board, removing copper particles, reducing copper, and removing the surface oxide scale after blackening. However, its process adjustability is small, the glue content is large, the process is mature, and the cost is relatively high. The abrasive shedding is fast. The present utility model adopts a radial non-woven fabric, which is a product formed by squeezing non-woven fabric materials through a swing piece and bonding and fixing the materials on a bakelite tube. It can be adjusted according to different usage conditions, and the cloth piece density, elasticity and the shape of the product can be changed. When contacting the PCB board surface, it is a single-piece contact, which can effectively prevent the brush wheel cloth pieces from scratching and falling off. The grinding is uniform, suitable for all grinding processes of the PCB board, with medium grinding cutting force, long service life, good conformability, large process adjustability, mature process, and high cost performance. The radial structure enables more cutting contacts, improving the hole opening cutting while ensuring the uniformity of the board surface cutting is not affected.

[0013] In the aforementioned grinding device for improving the burr at the hole opening, the deviation between the space height between the upper grinding brush wheel and the lower grinding brush wheel and the thickness of the PCB board is controlled within ±0.1 mm.

[0014] Technical effect: the deviation between the space height and the PCB board thickness is controlled within ±0.1mm, which is convenient for the upper and lower grinding brush wheels to grind the PCB board. If the space is too large, the grinding work cannot be completed; if it is too small, the PCB will be excessively ground and the grinding brush wheel will be squeezed. Strictly controlling the spacing facilitates the completion of grinding while smoothly conveying and protecting the grinding brush wheel.

[0015] In the aforementioned grinding device for improving the aperture burring, the first grinding brush wheel group, the second grinding brush wheel group and the third grinding brush wheel group are respectively connected to a second motor.

[0016] Technical effect: each of the three sets of grinding brush wheel groups is provided with a separate second motor, which is convenient for separate control and reverse control of the upper grinding brush wheel later, making it more convenient and flexible to use.

[0017] In the aforementioned grinding device for improving hole burring, the upper brush wheel and the lower brush wheel in the first brush wheel group are driven by the second motor to rotate along the rolling direction of the roller conveyor belt.

[0018] In the aforementioned grinding device for improving the burr of the hole, the upper brush wheels in the second and third brush wheel groups rotate in the opposite direction of the roller conveyor belt when driven by the corresponding second motor, and the lower brush wheels in the second and third brush wheel groups rotate in the direction of the roller conveyor belt when driven by the corresponding second motor.

[0019] Technical effect: The utility model does not adopt forward rotation in all the brush wheels. Instead, the reverse rotation of the upper brush wheels in the second and third groups is controlled, and the lower brush wheels in the second and third groups remain unchanged. The forward and reverse rotation of the plate horizontal transmission hole cutting will change the direction. The reverse rotation of the motor changes the mechanical brush stress to support the cutting and reduce the hole cutting. The reverse rotation of the motor can also prevent and eliminate only one side of the hole from being cut, improve and enhance the uniformity of the hole cutting, prevent the hole from being cut too large on one side and leaking the substrate, and prevent the hole from being abnormally shaped. The hole cape is significantly improved, and the poor cape is reduced from 15% to less than 3%.

[0020] In the aforementioned grinding device for improving hole burring, the second motor is connected to the corresponding grinding brush shaft by belt drive.

[0021] In the aforementioned grinding device for improving hole burr, the distance between each two adjacent PCB boards placed on the roller conveyor belt is ≥50mm.

[0022] The technical effect is that the distance between each plate in thin plate production is enlarged, leaving enough space to prevent the problem of motor reversal and easy jamming of the plate.

[0023] The beneficial effects of the utility model are:

[0024] The utility model is provided with three groups of grinding brush wheel sets. Compared with a single abrasive belt grinding wheel, the utility model also includes ceramic grinding and non-woven fabric grinding. Since a single abrasive belt cuts less at the hole opening, ceramics and non-woven fabrics are added. At the same time, the existing dry-rolled non-woven fabric grinding brush is replaced with a radial non-woven fabric grinding brush. The combination of multiple grinding methods can make use of their advantages and avoid their disadvantages, improving the uniformity of the hole opening, making the hole opening round and smooth, eliminating abnormal shaped gourd holes and figure-eight holes, improving the quality, and reducing the rejection rate.

[0025] In the utility model, the upper grinding brush wheel of the second group and the third group reverses to change the mechanical grinding brush cutting stress support point once. The reverse rotation can prevent and eliminate cutting only one side of the hole, improve the cutting uniformity of the hole opening, prevent excessive unilateral cutting of the hole opening and leakage of the base material, and abnormal shaped holes. The burr at the hole opening is significantly improved, and the burr defect rate is reduced from 15% to less than 3%.

[0026] The utility model prevents defects, improves the first-pass rate of the hole diameter in the PCB board factory, and improves the function detection efficiency; improves the grinding efficiency and quality at the current station, focuses on improving the hole diameter quality and preventing and reducing the rework of the hole diameter; reduces the rejection rate and saves the labor rework cost, improving the work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a grinding device for improving the burr at the hole opening according to an embodiment of the utility model;

[0028] Figure 2 is Figure 1 a schematic structural diagram of a single grinding brush wheel set in

[0029] Figure 3 is Figure 1 a side view of the first grinding brush wheel set in

[0030] Figure 4 is Figure 1 a side view of the second grinding brush wheel set in

[0031] Figure 5 is Figure 1 a side view of the third grinding brush wheel set in

[0032] In the figure: 1 - frame, 2 - roller conveyor belt, 3 - bracket, 4 - grinding brush shaft, 5 - upper grinding brush wheel, 6 - lower grinding brush wheel, 7 - first grinding brush wheel set, 8 - second grinding brush wheel set, 9 - third grinding brush wheel set, 10 - abrasive belt layer, 11 - ceramic layer, 12 - non-woven fabric layer. DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiment 1

[0033] A grinding device for improving the burr at the hole opening provided in this embodiment has a structure as shown in Figures 1-5As shown in the figure, it includes a frame 1. A roller conveyor belt 2 is provided on the frame 1, and a first motor for connecting and driving the roller conveyor belt 2 to work. A PCB board is provided on the roller conveyor belt 2. The distance between every two adjacent PCB boards is ≥ 50 mm. A grinding brush wheel set is embedded in the roller conveyor belt 2. A second motor for connecting and driving the grinding brush wheel set to rotate is installed on the frame 1. The second motor and the corresponding grinding brush shaft in the grinding brush wheel set are connected by belt drive. The PCB board is conveyed by the roller conveyor belt 2 to the grinding brush wheel set for grinding;

[0034] The grinding brush wheel set includes a bracket 3, a grinding brush shaft 4, an upper grinding brush wheel 5 and a lower grinding brush wheel 6. Two grinding brush shafts 4 are arranged parallel to each other up and down. The grinding brush shaft 4 is arranged on the frame 1 through the bracket 3 and is embedded in the roller conveyor belt 2. Where the grinding brush shaft is arranged on the roller conveyor belt, the roller is replaced by the grinding brush shaft. The upper grinding brush shaft is located above the roller conveyor belt, and the lower grinding brush shaft is located below the roller conveyor belt. The reserved space in the middle is for the PCB board to pass through. An upper grinding brush wheel 5 is provided on the upper grinding brush shaft 4, and a lower grinding brush wheel 6 is provided on the lower grinding brush shaft 4. A space for the PCB board to pass through is left between the upper grinding brush wheel 5 and the lower grinding brush wheel 6. The deviation between the space height and the PCB board thickness is controlled within ±0.1 mm. In order to achieve automation, sensors in the prior art can be installed on the upper and lower grinding brush wheels so that the distance between the upper and lower grinding brush wheels can be automatically sensed and adjusted. According to the board thickness detection and induction, the adjustment is automatically made to be within ±0.1 mm of the positive and negative deviation from the PCB thickness. The grinding brush wheel set is provided with three groups, including the first grinding brush wheel group 7, the second grinding brush wheel group 8 and the third grinding brush wheel group 9 which are arranged parallel at intervals. On the outer surfaces of the upper grinding brush wheel 5 and the lower grinding brush wheel 6 in the first grinding brush wheel group 7, a sand belt layer 10 for grinding is detachably wound. On the outer surfaces of the upper grinding brush wheel 5 and the lower grinding brush wheel 6 in the second grinding brush wheel group 8, a ceramic layer 11 for grinding is adhered. On the outer surfaces of the upper grinding brush wheel 5 and the lower grinding brush wheel 6 in the third grinding brush wheel group 9, a non-woven fabric layer 12 for grinding is adhered. The non-woven fabric in the non-woven fabric layer 12 is a radial 600-mesh non-woven fabric;

[0035] The first grinding brush wheel group 7, the second grinding brush wheel group 8 and the third grinding brush wheel group 9 are respectively connected with a second motor and are controlled separately. The upper grinding brush wheel 5 and the lower grinding brush wheel 6 in the first grinding brush wheel group 7 rotate along the rolling direction of the roller conveyor belt 2 under the drive of the second motor. The upper grinding brush wheels 5 in the second grinding brush wheel group 8 and the third grinding brush wheel group 9 rotate in the direction opposite to the rolling direction of the roller conveyor belt 2 respectively under the drive of the corresponding second motors. The lower grinding brush wheels 6 in the second grinding brush wheel group 8 and the third grinding brush wheel group 9 rotate in the rolling direction of the roller conveyor belt 2 respectively under the drive of the corresponding second motors.

[0036] In this embodiment, after normal brushing, the grinding wheel is tested for grinding marks. If the marks meet the requirement of 8 - 12 mm, it can be used normally. This is a test that must be done before conventional grinding to ensure that the brush is flat and prevent abnormal horizontal line clamping caused by the reverse rotation of the brush motor. For PCB boards with a thickness ≤ 1.0 mm, first-piece confirmation is required. During mechanical grinding, the induction thickness conveyor will extract the board. If the thickness is greater than 1.0 mm, it is normal. The gap between the grinding boards needs to be ≥ 50 mm. Only after the first-piece is confirmed to be qualified can mass production be carried out.

[0037] In addition to the above embodiments, the present utility model can also have other implementation manners. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present utility model.

Claims

1. A grinding device for improving burrs at the orifice, comprising a frame (1), wherein a roller conveyor belt (2) for conveying PCB boards is arranged on the frame (1), and a first motor for connecting and driving the roller conveyor belt (2) to work, and is characterized in that: A grinding brush wheel set is embedded in the roller conveyor belt (2), and a second motor for connecting and driving the grinding brush wheel set to rotate is installed on the machine frame (1). The PCB board is conveyed to the grinding brush wheel set by the roller conveyor belt (2) for grinding; The grinding brush wheel set includes a bracket (3), a grinding brush shaft (4), an upper grinding brush wheel (5) and a lower grinding brush wheel (6). Two grinding brush shafts (4) are arranged in parallel up and down. The grinding brush shafts (4) are arranged on the machine frame (1) through the bracket (3) and embedded in the roller conveyor belt (2). The upper grinding brush wheel (5) is arranged on the upper grinding brush shaft (4), and the lower grinding brush wheel (6) is arranged on the lower grinding brush shaft (4). A space for the PCB board to pass through is left between the upper grinding brush wheel (5) and the lower grinding brush wheel (6); Three groups of grinding brush wheel sets are provided, including a first grinding brush wheel set (7), a second grinding brush wheel set (8) and a third grinding brush wheel set (9) which are arranged in parallel at intervals. A sand belt layer (10) for grinding is provided on the outer surfaces of the upper grinding brush wheel (5) and the lower grinding brush wheel (6) in the first grinding brush wheel set (7). A ceramic layer (11) for grinding is provided on the outer surfaces of the upper grinding brush wheel (5) and the lower grinding brush wheel (6) in the second grinding brush wheel set (8). A non-woven fabric layer (12) for grinding is provided on the outer surfaces of the upper grinding brush wheel (5) and the lower grinding brush wheel (6) in the third grinding brush wheel set (9).

2. The grinding device for improving the burr at the orifice according to claim 1, wherein: The non-woven fabric in the non-woven fabric layer (12) is a radial 600-mesh non-woven fabric.

3. The grinding device for improving the burr at the orifice according to claim 1, characterized in that: The deviation between the space height between the upper grinding brush wheel (5) and the lower grinding brush wheel (6) and the thickness of the PCB board is controlled within ±0.1 mm.

4. The grinding device for improving the burr at the orifice according to claim 1, wherein: Each of the first grinding brush wheel set (7), the second grinding brush wheel set (8) and the third grinding brush wheel set (9) is connected to one of the second motors.

5. The grinding device for improving the burr at the orifice according to claim 4, wherein: The upper grinding brush wheel (5) and the lower grinding brush wheel (6) in the first grinding brush wheel set (7) rotate along the rolling direction of the roller conveyor belt (2) under the drive of the second motor.

6. The grinding device for improving the burr at the orifice according to claim 4, characterized in that: The upper grinding brush wheels (5) in the second grinding brush wheel set (8) and the third grinding brush wheel set (9) rotate in the direction opposite to the rolling direction of the roller conveyor belt (2) respectively under the drive of the corresponding second motor, and the lower grinding brush wheels (6) in the second grinding brush wheel set (8) and the third grinding brush wheel set (9) rotate in the rolling direction of the roller conveyor belt (2) respectively under the drive of the corresponding second motor.

7. The grinding device for improving the burr at the orifice according to claim 1, wherein: The second motor and the corresponding grinding brush shaft (4) are connected by belt drive.

8. The grinding device for improving the burr at the orifice according to claim 1, wherein: The distance between every two adjacent PCB boards placed on the roller conveyor belt (2) is ≥50 mm.

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