A circuit board clamping fixture

Abstract

The present invention relates to a circuit board clamping fixture, which is composed of a substrate and at least one circuit board adsorption unit. A placement groove consistent with the number of circuit board adsorption units is extended downward from the upper plane of the substrate to be used for embedding the circuit board adsorption unit. The circuit board adsorption unit includes a base plate, a carrier plate, a pipe joint and a vacuum generator. The carrier plate and the base plate are stacked in sequence from top to bottom and fixed as a whole. A plurality of independent ventilation grooves are extended downward from the upper plane of the base plate, which are surrounded by the carrier plate to form a plurality of independent ventilation cavities. Corresponding to each ventilation cavity, an adsorption hole communicating with the ventilation cavity is opened on the carrier plate. The number of pipe joints is set to be multiple, which are inserted on the carrier plate and communicate with the ventilation cavity one by one. The vacuum generator is connected to the pipe joint. When the vacuum generator is started, negative pressure is generated in the ventilation cavity, and the adsorption and fixation of the circuit board is achieved through the adsorption hole.

Description

Technical Field

[0001] The invention relates to the technical field of non-standard equipment manufacturing, in particular to a circuit board clamping fixture. Background Art

[0002] Circuit boards are important electronic components, supporting electronic components and providing electrical connections for electronic components. With the rapid development of the electronics industry, printed circuit boards are also developing rapidly towards multi-layer and high-density.

[0003] The surface quality of the circuit board has a crucial impact on its application performance. In the existing technology, the circuit board is usually inspected by manpower to determine whether its size and shape meet the requirements, and to observe whether there are leaking solder joints, impurities and stains on the front and back. However, the standards of the inspected products include IPC international general standards and different customer requirements. Therefore, in order to ensure the qualified rate of the outflow products, it is often necessary to educate and train the inspectors so that they can master the standards and inspection methods. However, even with a lot of training, manual inspection still has problems such as high leakage rate and low efficiency. For this reason, our company has developed a circuit board visual inspection system.

[0004] Before the formal inspection of the circuit board, it needs to be lowered and placed securely on the inspection table, and the position must be locked. Then, the image of its surface is captured by a high-speed camera. In the past, mechanical clamping was usually used to fix the circuit board. However, in the actual operation, the clamping force is not easy to quantitatively control due to the influence of factors such as the operator's work experience and emotions. When the clamping force is too small, the circuit board cannot be effectively clamped, which makes it very easy to move the position during the transfer process, thereby affecting the accuracy of the image acquisition position; when the clamping force is too large, the force-applying end of the clamp is very likely to damage the circuit board, and even affect the normal transmission function of the circuit or signal. Therefore, it is urgent for technical personnel to solve the above problems. Summary of the invention

[0005] Therefore, in view of the above-mentioned existing problems and defects, the designers of the present invention collected relevant information, conducted multiple evaluations and considerations, and continued to experiment and modify the circuit board clamping fixture after many years of R&D experience in this industry, which ultimately led to the emergence of the circuit board clamping fixture.

[0006] In order to solve the above technical problems, the present invention relates to a circuit board clamping fixture, which is composed of a substrate and at least one circuit board adsorption unit. A placement groove consistent with the number of circuit board adsorption units extends downward from the upper plane of the substrate to be used to embed the circuit board adsorption unit. The circuit board adsorption unit includes a base plate, a carrier plate, a pipe joint and a vacuum generator. The carrier plate and the base plate are stacked in sequence from top to bottom and fixed as a whole. A plurality of independent ventilation grooves extend downward from the upper plane of the base plate, which are assisted by the function of the carrier plate to jointly surround a plurality of independent ventilation cavities. Corresponding to each ventilation cavity, an adsorption hole communicating with the ventilation cavity is opened on the carrier plate. The number of pipe joints is set to be multiple, which are inserted on the carrier plate and communicate with the ventilation cavity one by one. The vacuum generator is connected to the pipe joint. When the vacuum generator is started, negative pressure is generated in the ventilation cavity, and the adsorption and fixation of the circuit board is achieved through the adsorption hole.

[0007] As a further improvement of the technical solution of the present invention, the circuit board adsorption unit also includes a first position adjustment part and a second position adjustment part. The first position adjustment part and the second position adjustment part are both supported by the substrate to push the circuit board to move along the front-to-back direction and the left-to-right direction respectively.

[0008] As a further improvement of the technical solution of the present invention, the first position adjustment part includes a first linear motion element, a first load-bearing transition piece, a first slide rail slider assembly and a first push-out column. The first linear motion element is detachably fixed to the bottom wall of the base plate. The first load-bearing transition piece is directly driven by the first linear motion element, and performs a directional displacement movement along the front-to-back direction under the action of the first slide rail slider assembly. The first slide rail slider assembly is arranged between the first load-bearing transition piece and the base plate. A first long strip avoidance gap extending along the front-to-back direction is provided on the bearing plate, and also completely penetrates the bottom plate. The first push-out column is inserted into the first long strip avoidance gap, and it is dragged by the first load-bearing transition piece.

[0009] As a further improvement of the technical solution of the present invention, the first position adjustment part also includes a first sliding block and a first columnar spring. A first sliding cavity adapted to the shape of the first sliding block extends downward from the upper plane of the first load-bearing transition piece. The first sliding block is fixed as a whole with the first push column and is built into the first sliding cavity. The first columnar spring is built into the first sliding cavity and always applies an elastic rearward thrust to the first sliding block.

[0010] As a further improvement of the technical solution of the present invention, the first position adjustment part also includes a first limit pin. The first limit pin crosses the first sliding block. The left and right side walls of the first load-bearing transition piece are respectively provided with a first long sliding notch and a second long sliding notch extending along the front-to-back direction and both intersecting the first sliding cavity. The first limit pin is simultaneously inserted into the first long sliding notch and the second long sliding notch, and slides forward and backward under the joint action of the first columnar spring and the first linear motion element.

[0011] As a further improvement of the technical solution of the present invention, the first linear motion element is preferably any one of a cylinder, a hydraulic cylinder or a linear motor.

[0012] As a further improvement of the technical solution of the present invention, the second position adjustment part includes a second linear motion element, a second load-bearing transition piece, a second slide rail slider assembly and a second push-out column. The second linear motion element is detachably fixed to the bottom wall of the base plate. The second load-bearing transition piece is directly driven by the second linear motion element, and performs a directional displacement movement along the left-right direction under the action of the second slide rail slider assembly. The second slide rail slider assembly is arranged between the second load-bearing transition piece and the base plate. A second long strip avoidance gap extending along the left-right direction is provided on the bearing plate, and also completely penetrates the bottom plate. The second push-out column is inserted into the second long strip avoidance gap, and it is fixed on the second load-bearing transition piece.

[0013] As a further improvement of the technical solution of the present invention, the second position adjustment part also includes a limit seat and a second columnar spring. The limit seat is detachably fixed to the bottom wall of the base plate and corresponds to the second slide rail slider assembly. The second columnar spring is installed on the limit seat and can apply an elastic push force to the second load-bearing transition piece along the left and right directions.

[0014] As a further improvement of the technical solution of the present invention, the second linear motion element is preferably any one of a cylinder, a hydraulic cylinder or a linear motor.

[0015] As a further improvement of the technical solution of the present invention, the number of the circuit board adsorption units is set to 2, and they are placed side by side along the left-right direction.

[0016] Compared with the traditional mechanical clamping method, in the technical solution disclosed in the present invention, a vacuum adsorption method is used to fix the circuit board, by opening a ventilation groove on the bottom plate, and the carrier plate is overlapped to form a ventilation cavity. The adsorption holes connected to the ventilation cavity are used to directly adsorb the circuit board. In this way, under the premise of ensuring good positioning of the circuit board, the phenomenon of the circuit board being crushed during the clamping process is effectively avoided. In addition, in the actual application process, it is convenient to modify the design of the circuit board clamping fixture according to the actual situation on site to adapt to circuit boards of various models and specifications. When the model of the pre-detected circuit board changes, it is convenient to form new adsorption holes according to the specific direction of the circuit board (and seal the old adsorption holes if necessary). BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a three-dimensional schematic diagram of the first embodiment of the circuit board clamping fixture in the present invention.

[0019] Figure 2 It is an exploded schematic diagram of the first embodiment of the circuit board clamping fixture in the present invention.

[0020] Figure 3 yes Figure 1 Top view of the .

[0021] Figure 4 yes Figure 3 AA section view.

[0022] Figure 5 yes Figure 3 BB cross-sectional view.

[0023] Figure 6 yes Figure 1 Bottom view of .

[0024] Figure 7 It is a three-dimensional schematic diagram of the first position adjustment portion in the first embodiment of the circuit board clamping fixture of the present invention.

[0025] Figure 8 It is a three-dimensional schematic diagram of the second position adjustment portion in the first embodiment of the circuit board clamping fixture of the present invention.

[0026] Fig. 9 It is a three-dimensional schematic diagram of the bottom plate in the first embodiment of the circuit board clamping fixture of the present invention.

[0027] Fig.10 It is a three-dimensional schematic diagram of a carrier plate in the first embodiment of the circuit board clamping fixture of the present invention.

[0028] Fig.11 It is a three-dimensional schematic diagram of the first load-bearing transition piece in the first embodiment of the circuit board clamping fixture of the present invention.

[0029] Fig.12 It is a three-dimensional schematic diagram of a substrate in the first embodiment of the circuit board clamping fixture of the present invention.

[0030] Fig.13 It is a three-dimensional schematic diagram of a second embodiment of the circuit board clamping fixture in the present invention.

[0031] Fig.14 It is a schematic diagram of the installation position of the circuit board clamping fixture relative to the circuit board visual inspection system in the present invention.

[0032] 1-substrate; 11-placement groove; 2-circuit board adsorption unit; 21-bottom plate; 211-ventilation groove; 22-carrying plate; 221-adsorption hole; 222-first long strip avoidance gap; 223-second long strip avoidance gap; 23-pipe joint; 24-ventilation cavity; 25-first position adjustment part; 251-first linear motion element; 252-first load-bearing transition piece; 2521-first sliding cavity; 2522-first long strip sliding Shift notch; 2523-second long sliding notch; 253-first slide rail slider assembly; 254-first push column; 255-first sliding block; 256-first columnar spring; 257-first limit pin; 26-second position adjustment part; 261-second linear motion element; 262-second load-bearing transition piece; 263-second slide rail slider assembly; 264-second push column; 265-limit seat; 266-second columnar spring. DETAILED DESCRIPTION

[0033] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "left", "right", "up", "down", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0034] In order to facilitate those skilled in the art to fully understand the technical solutions disclosed in the present invention, the present invention is further described in detail below in conjunction with specific embodiments. Figure 1 , Figure 2The three-dimensional schematic diagram and the exploded schematic diagram of the first embodiment of the circuit board clamping fixture in the present invention are respectively shown. It can be seen that it is composed of a substrate 1 and a circuit board adsorption unit 2. Among them, the upper plane of the substrate 1 extends downward to have placement grooves 11 consistent with the number of circuit board adsorption units 2, which are used to embed the circuit board adsorption unit 2. The circuit board adsorption unit 2 includes a bottom plate 21, a carrier plate 22, a pipe joint 23 and a vacuum generator (not shown in the figure). The carrier plate 22 and the bottom plate 21 are stacked in sequence from top to bottom and fixed as a whole. A plurality of independent ventilation grooves 211 extend downward from the upper plane of the bottom plate 21, which are assisted by the carrier plate 22 to form a plurality of independent ventilation cavities 24. Corresponding to each ventilation cavity 24, an adsorption hole 221 communicating with the ventilation cavity 24 is opened on the carrier plate 22. The number of pipe joints 23 is set to be multiple, which are inserted on the carrier plate 22 and communicate with the ventilation cavity 24 one by one. The vacuum generator is connected to the pipe joint 23 (such as Fig. 9 , 10 , 12 ). When the vacuum generator is activated, negative pressure is generated in the ventilation cavity 24 , and the circuit board is adsorbed and fixed through the adsorption holes 221 .

[0035] In the technical solution disclosed in the present invention, the circuit board is fixed by vacuum adsorption, by opening a ventilation groove 211 on the bottom plate 21, and the carrier plate 22 is overlapped to form a ventilation cavity 24. The adsorption hole 221 connected to the ventilation cavity 24 is used to directly adsorb the circuit board. In this way, under the premise of ensuring good positioning of the circuit board, the phenomenon of the circuit board being crushed during the clamping process is effectively avoided. In addition, in the actual application process, it is convenient to modify the design of the circuit board clamping fixture according to the actual situation on site to adapt to circuit boards of various models and specifications. When the model of the pre-detected circuit board changes, it is convenient to form a new adsorption hole 221 according to the specific direction of the circuit board (if necessary, the old adsorption hole is blocked).

[0036] It is known that the accuracy of the position of the specific imaging area has a crucial impact on the subsequent circuit board appearance inspection results. When the imaging area deviates greatly from the original imaging reference position, the imaging image cannot be compared and analyzed with the standard image, which leads to the failure of the detection operation. In view of this, the circuit board adsorption unit 2 also includes a first position adjustment part 25 and a second position adjustment part 26. The first position adjustment part 25 and the second position adjustment part 26 are both supported by the substrate 1 to push the circuit board to move along the front-to-back direction and the left-to-right direction (such as Figure 2 , 3When the circuit board is placed on the carrier plate 22, before the vacuum generator is started, the first position adjustment unit 25 and the second position adjustment unit 26 need to be started simultaneously to push the circuit board in the front-to-back direction and the left-to-right direction respectively until the circuit board is completely in contact with the positioning reference set on the carrier plate 22, thus achieving accurate positioning of the circuit board.

[0037] It is known that the first position adjustment part 25 can adopt a variety of design methods to achieve the push-up action on the circuit board. However, an implementation scheme with a simple design structure, easy implementation, high action sensitivity, and convenient later maintenance is recommended here, which is as follows: the first position adjustment part 25 includes a first linear motion element 251, a first load-bearing transition piece 252, a first slide rail slider assembly 253 and a first push-up column 254. The first linear motion element 251 is detachably fixed to the bottom wall of the substrate 1. The first load-bearing transition piece 252 is directly driven by the first linear motion element 251, and performs a directional displacement movement along the front-to-back direction under the action of the first slide rail slider assembly 253. The first slide rail slider assembly 253 is arranged between the first load-bearing transition piece 252 and the substrate 1. A first long strip avoidance gap 222 extending along the front-to-back direction is opened on the bearing plate 22, and also penetrates the bottom plate 21 at the same time. The first push-up column 254 is inserted into the first long strip avoidance gap 222, and it is dragged by the first load-bearing transition piece 252. The first push pin 254 must extend beyond the upper plane of the carrier plate 22 by a distance which is generally greater than the thickness of the circuit board itself (e.g. Figure 3 , 4 , 6, and 7).

[0038] In addition, as a further optimization of the structure of the first position adjustment portion 25, a first sliding block 255 and a first columnar spring 256 are further provided according to actual conditions. Fig.11 As shown in FIG. 1 , a first sliding cavity 2521 matching the shape of the first sliding block 255 extends downward from the upper plane of the first load-bearing transition piece 252. The first sliding block 255 is fixed as a whole with the first push column 254, and is built into the first sliding cavity 2521. The first columnar spring 256 is built into the first sliding cavity 2521, and always applies an elastic rearward thrust to the first sliding block 255 (such as Figure 3 , 4 , 6, and 7). In this way, no matter the first linear motion element 251 is a hydraulic cylinder, a pneumatic cylinder, or a linear motor, the ejection force acting on the circuit board is an elastic force. The first ejection column 254 is always exerted an elastic ejection force on the circuit board by the first columnar spring 256, thereby effectively preventing the circuit board from being squeezed and damaged by the rigid force.

[0039] In order to ensure that the first sliding block 255 has good guiding performance when sliding along the first sliding cavity 2521 and avoid direct wear between the first sliding block 255 and the first sliding cavity 2521, a first stop pin 257 is further provided as a further optimization of the structure of the first position adjustment part 25. The first stop pin 257 crosses the first sliding block 255. Fig.11 As shown in the figure, the left and right side walls of the first load-bearing transition member 252 are respectively provided with a first long sliding notch 2522 and a second long sliding notch 2523 extending along the front-to-back direction and both intersecting the first sliding cavity 2521. The first limit pin 257 is simultaneously provided in the first long sliding notch 2522 and the second long sliding notch 2523, and slides forward and backward under the joint action of the first columnar spring 256 and the first linear motion element 251 (as shown in FIG. Figure 3 , 4 , 6, and 7).

[0040] Analogous to the above-mentioned first position adjustment part 25, the second position adjustment part 26 is mainly composed of several parts such as a second linear motion element 261, a second load-bearing transition piece 262, a second slide rail slider assembly 263 and a second push-out column 264. Among them, the second linear motion element 261 is detachably fixed to the bottom wall of the substrate 1. The second load-bearing transition piece 262 is directly driven by the second linear motion element 261, and performs a directional displacement movement along the left and right directions under the action of the second slide rail slider assembly 263. The second slide rail slider assembly 263 is arranged between the second load-bearing transition piece 262 and the substrate 1. A second long strip avoidance gap 223 extending along the left and right directions is opened on the supporting plate 22, and also passes through the bottom plate 21 at the same time. The second push-out column 264 is inserted into the second long strip avoidance gap 223, and it is fixed on the second load-bearing transition piece 262 (such as Figure 3 , 5 , 6, and 8).

[0041] Of course, in order to prevent the circuit board from being damaged by the rigid extrusion force, the second position adjustment part 26 can be additionally provided with a limit seat 265 and a second columnar spring 266 according to the actual situation. The limit seat 265 is detachably fixed on the bottom wall of the substrate 1 and corresponds to the second slide rail slider assembly 263. The second columnar spring 266 is installed on the limit seat 265 and can apply an elastic push force on the second load-bearing transition member 262 along the left and right directions (such as Figure 3 , 5 , 6, and 8). In this way, no matter the second linear motion element 261 is a hydraulic cylinder, a pneumatic cylinder, or a linear motor, the ejection force acting on the circuit board is an elastic force. Under the action of the second columnar spring 266, the second ejection column 264 always applies an elastic ejection force on the circuit board.

[0042] Fig.13 The figure shows a three-dimensional schematic diagram of the second embodiment of the circuit board clamping fixture in the present invention. The difference between the second embodiment and the first embodiment is that the number of circuit board adsorption units 2 is set to 2, and they are arranged side by side in the left and right directions. In this way, in the actual inspection process, when the high-speed camera takes an image of the circuit board adsorbed by one of the circuit board adsorption units 2, the staff can replace the circuit board adsorbed by the other circuit board adsorption unit 2, thereby ensuring that the high-speed camera always maintains a continuous imaging state, thereby effectively improving the working efficiency of the circuit board visual inspection system.

[0043] Finally, it should be noted that in order to facilitate those skilled in the art to fully understand the technical solutions disclosed in the present invention, Fig.14 A schematic diagram of the installation position of the circuit board clamping fixture relative to the circuit board visual inspection system in the present invention is also shown.

[0044] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A circuit board clamping fixture, characterized in that: It is composed of a substrate and at least one circuit board adsorption unit; the upper plane of the substrate extends downward to have placement grooves that are consistent with the number of the circuit board adsorption units, so as to embed the circuit board adsorption units; The circuit board adsorption unit includes a bottom plate, a carrier plate, a pipe joint and a vacuum generator; the carrier plate and the bottom plate are stacked in sequence from top to bottom and fixed as a whole; a plurality of independent ventilation grooves extend downward from the upper plane of the bottom plate, and the bearing plate is used to jointly surround a plurality of independent ventilation cavities; corresponding to each ventilation cavity, an adsorption hole communicating with the ventilation cavity is opened on the carrier plate; the number of the pipe joints is set to be multiple, which are inserted on the carrier plate and communicate with the ventilation cavities one by one; the vacuum generator is connected to the pipe joint; when the vacuum generator is started, negative pressure is generated in the ventilation cavity, and the circuit board is adsorbed and fixed by the adsorption hole; The circuit board adsorption unit further includes a first position adjustment part and a second position adjustment part; the first position adjustment part and the second position adjustment part are both supported by the substrate to push the circuit board to move along the front-to-back direction and the left-to-right direction respectively; The first position adjustment part includes a first linear motion element, a first load-bearing transition piece, a first slide rail slider assembly and a first push-out column; the first linear motion element is detachably fixed to the bottom wall of the base plate; the first load-bearing transition piece is directly driven by the first linear motion element, and performs directional displacement movement along the front-rear direction under the action of the first slide rail slider assembly; the first slide rail slider assembly is arranged between the first load-bearing transition piece and the base plate; a first long strip avoidance gap extending along the front-rear direction is provided on the bearing plate, and also completely penetrates the base plate; the first push-out column is inserted into the first long strip avoidance gap, and is dragged by the first load-bearing transition piece; The second position adjustment part includes a second linear motion element, a second load-bearing transition piece, a second slide rail slider assembly and a second push-out column; the second linear motion element is detachably fixed to the bottom wall of the base plate; the second load-bearing transition piece is directly driven by the second linear motion element, and performs directional displacement movement along the left-right direction under the action of the second slide rail slider assembly; the second slide rail slider assembly is arranged between the second load-bearing transition piece and the base plate; a second long strip avoidance gap extending along the left-right direction is provided on the supporting plate and also completely penetrates the bottom plate; the second push-out column is inserted into the second long strip avoidance gap, and is fixed to the second load-bearing transition piece.

2. The circuit board clamping fixture according to claim 1, characterized in that: The first position adjustment part also includes a first sliding block and a first columnar spring; a first sliding cavity adapted to the shape of the first sliding block extends downward from the upper plane of the first load-bearing transition piece; the first sliding block and the first push column are fixed as a whole and built into the first sliding cavity; the first columnar spring is built into the first sliding cavity and always applies an elastic rearward thrust to the first sliding block.

3. The circuit board clamping fixture according to claim 2, characterized in that: The first position adjustment part also includes a first limit pin; the first limit pin crosses the first sliding block; a first long sliding notch and a second long sliding notch are respectively opened on the left and right side walls of the first load-bearing transition piece, extending along the front-to-back direction and both communicating with the first sliding cavity; the first limit pin is simultaneously passed through the first long sliding notch and the second long sliding notch, and slides forward and backward under the joint action of the first columnar spring and the first linear motion element.

4. The circuit board clamping fixture according to claim 1, characterized in that: The first linear motion element is any one of a cylinder, a hydraulic cylinder or a linear motor.

5. The circuit board clamping fixture according to claim 1, characterized in that: The second position adjustment portion also includes a limit seat and a second columnar spring; the limit seat is detachably fixed to the bottom wall of the substrate and corresponds to the second slide rail slider assembly; the second columnar spring is installed on the limit seat and can apply an elastic pushing force to the second load-bearing transition piece along the left and right directions.

6. The circuit board clamping fixture according to claim 1, characterized in that: The second linear motion element is any one of a cylinder, a hydraulic cylinder or a linear motor.

7. The circuit board clamping fixture according to any one of claims 1 to 6, characterized in that: The number of the circuit board adsorption units is set to 2, and they are arranged side by side along the left-right direction.

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