SMT printing machine scraper

Abstract

The utility model relates to the technical field of printing machine scrapers, in particular to an SMT printing machine scraper which comprises a connecting box, a plurality of adjusting assemblies are arranged at the lower end of the connecting box, pressure sensors are arranged on the adjusting assemblies, buffer blocks are arranged at the lower ends of the adjusting assemblies, and a supporting plate is arranged at the lower ends of the buffer blocks. A main knife is arranged on the bottom wall of the supporting plate, an auxiliary knife sleeve is arranged at the lower end of the main knife, the auxiliary knife sleeve is matched with the main knife and is in damping sliding connection with the main knife, a connecting shaft is arranged at the upper end of the connecting box, the adjusting assembly comprises a control box, a motor, a supporting rod, an adjusting rod and an adjusting block, and baffles are arranged at the two ends of the bottom wall of the supporting plate. The buffer block is of a multi-layer composite elastomer structure, dynamic balance of pressure in different areas of the scraper is achieved, impact noise generated when the scraper works is effectively reduced, and the scraper is particularly suitable for precise printing of high-viscosity solder paste.

Description

Technical Field

[0001] This utility model relates to the field of printing press squeegee technology, specifically to a squeegee for an SMT printing press. Background Technology

[0002] As we all know, the existing surface mount technology is developing rapidly. The miniaturization, high density and multi-functionality of electronic components have put forward higher requirements for printing processes. Solder paste printing, as the core link in SMT production, directly affects the soldering quality and product reliability. In the solder paste printing process, the squeegee, as a key execution component, directly determines the printing accuracy, uniformity and stencil life of the solder paste.

[0003] Although traditional scraper designs have undergone multiple iterations, they still exhibit problems such as inaccurate pressure control, insufficient dynamic adaptability, and uneven wear in high-speed, high-precision production scenarios.

[0004] Specifically, existing SMT printing machine squeegees mostly adopt a rigid connection structure and a single squeegee blade design. The squeegee is connected to the drive mechanism through a fixed bracket, lacking real-time monitoring and closed-loop control. Pressure adjustment relies on mechanical springs or manual fine-tuning devices, which easily leads to unavoidable pressure fluctuations during the printing process. At the same time, the squeegee blade needs to be replaced as a whole after it wears out, resulting in high maintenance costs and seriously affecting the expansion of the process window. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this utility model provides a squeegee for an SMT printing machine.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: an SMT printing machine squeegee, including a connecting box, a plurality of adjustment components are provided at the lower end of the connecting box, each adjustment component is provided with a pressure sensor, a buffer block is provided at the lower end of the adjustment component, a support plate is provided at the lower end of the buffer block, a main blade is provided on the bottom wall of the support plate, an auxiliary blade sleeve is provided at the lower end of the main blade, the auxiliary blade sleeve is adapted to the main blade and is damped and slidably connected, and a connecting shaft is provided at the upper end of the connecting box.

[0009] To achieve precise vertical displacement control, this utility model improves upon the following: the adjustment assembly includes a control box, a motor, a support rod, an adjustment rod, and an adjustment block. The control box is connected to the connecting box, the motor is inside the control box, the support rod is at the lower end of the motor, the adjustment rod passes through the support rod and is connected to the output end of the motor, the adjustment block is on the adjustment rod and threadedly connected to it, the inner sidewall of the support rod fits against the adjustment block, and the buffer block is connected to the bottom wall of the adjustment block.

[0010] To prevent solder paste from overflowing during the printing process, the present invention is improved by providing baffles at both ends of the bottom wall of the support plate.

[0011] In order to capture the dynamic pressure changes between the scraper and the template in real time, the present invention has the following improvement: the pressure sensor is a miniature piezoelectric ceramic sensor.

[0012] To provide contact stability, the present invention is improved in that the buffer block is a multi-layer composite elastomer structure, including an upper silicone layer, a middle polyurethane honeycomb layer and a lower rubber wear-resistant layer.

[0013] To ensure the overall toughness of the blade, the present invention has the following improvements: the main blade is a gradient cemented carbide blade with a diamond-like coating on its cutting edge.

[0014] To reduce the adhesion rate of solder paste residue, the present invention is improved by providing a nano-oleophobic coating on the outer surface of the baffle.

[0015] In order to dynamically correct the motor output angle, the present invention has the following improvement: the motor is a closed-loop control stepper motor.

[0016] (III) Beneficial Effects

[0017] Compared with the prior art, this utility model provides a squeegee for an SMT printing machine, which has the following beneficial effects:

[0018] This SMT printer squeegee is equipped with multiple adjustment components. The motor drives the adjustment rod to rotate, which in turn moves the threaded adjustment block vertically along the inner wall of the support rod. The miniature piezoelectric ceramic sensor of each adjustment component monitors the contact pressure of the corresponding area of ​​the squeegee in real time. When local deformation of the PCB board or uneven distribution of solder paste is detected, the system independently adjusts the output torque of each motor to change the downward stroke of the adjustment block, thereby achieving dynamic balance of pressure in different areas of the squeegee.

[0019] The system is equipped with a composite buffer block. When the scraper contacts the template, it absorbs the impact energy step by step through a hierarchical structure. The silicone layer filters high-frequency vibration, the polyurethane honeycomb layer disperses lateral stress, and the rubber layer maintains stable contact between the support plate and the template. This effectively reduces the impact noise of the scraper during operation and avoids solder paste splashing caused by sudden pressure changes.

[0020] The main blade and the auxiliary blade sleeve are connected by a damping sliding joint to form a flexible fit. During the blade's movement, the rigid scraping effect of the main blade edge is ensured, while the flexible compensation of the auxiliary blade sleeve eliminates the edge trailing phenomenon. It is especially suitable for precision printing of high-viscosity solder paste. Attached Figure Description

[0021] Figure 1 This is a first-view schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a second-view schematic diagram of the structure of this utility model;

[0023] Figure 3 This is a partial schematic diagram of the structure of this utility model from a third-view perspective;

[0024] Figure 4 This is an exploded view of the structural adjustment component of this utility model.

[0025] In the diagram: 1. Connecting box; 2. Connecting shaft; 3. Control box; 4. Support rod; 5. Buffer block; 6. Pressure sensor; 7. Support plate; 8. Baffle; 9. Main blade; 10. Auxiliary blade sleeve; 11. Adjusting rod; 12. Motor; 13. Adjusting block. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] Please see Figure 1-4 A squeegee for an SMT printing machine includes a connecting box 1. Multiple adjustment components are arranged at the lower end of the connecting box 1. Each adjustment component is equipped with a pressure sensor 6. A buffer block 5 is arranged at the lower end of the adjustment component. A support plate 7 is arranged at the lower end of the buffer block 5. A main blade 9 is arranged on the bottom wall of the support plate 7. An auxiliary blade sleeve 10 is arranged at the lower end of the main blade 9. The auxiliary blade sleeve 10 is adapted to the main blade 9 and is slidably connected with damping. A connecting shaft 2 is arranged at the upper end of the connecting box 1. The adjustment components include a control box 3, a motor 12, a support rod 4, an adjustment rod 11, and an adjustment block 13. Box 3 is connected to the connecting box 1. The motor 12 is inside the control box 3. The support rod 4 is at the lower end of the motor 12. The adjusting rod 11 passes through the support rod 4 and is connected to the output end of the motor 12. The adjusting block 13 is on the adjusting rod 11 and is threadedly connected to it. The inner side wall of the support rod 4 is in contact with the adjusting block 13. The buffer block 5 is connected to the bottom wall of the adjusting block 13. The pressure sensor 6 is a miniature piezoelectric ceramic sensor. The buffer block 5 is a multi-layer composite elastomer structure, including an upper silicone layer, a middle polyurethane honeycomb layer, and a lower rubber wear-resistant layer.

[0030] During use, the entire squeegee module is installed onto the printing press motion mechanism via the connecting shaft 2 at the top of the connecting box 1 (this is a mature technology and will not be elaborated upon here), achieving precise positioning and power transmission of the squeegee. The auxiliary squeegee sleeve 10 is fitted under the main squeegee 9 using a damped sliding method. Upon startup, the miniature piezoelectric ceramic sensors of each adjustment component automatically complete zero-point calibration. The printing press drives the squeegee downward. When the main squeegee 9 first contacts the stencil template, the silicone layer of the buffer block 5 first deforms to absorb the impact, and the polyurethane honeycomb layer then disperses the lateral stress, preventing rigid collision damage to the template. Simultaneously, the piezoelectric ceramic sensors in multiple adjustment components monitor the pressure changes in various areas of the squeegee in real time. When a local depression in the PCB substrate or uneven tension of the stencil is detected (such as a drop in pressure in the edge area), the sensor transmits a signal to the control box 3, and the control system adjusts accordingly. According to the pressure deviation value, the motor 12 of the corresponding partition is driven to rotate. The output of the motor 12 drives the adjustment rod 11 to rotate. Through the threaded engagement with the adjustment block 13, under the limit of the support rod 4, the vertical displacement compensation of the adjustment block 13 is realized. For example, (motor 12 rotates forward → adjustment block 13 moves down → pressure in the area of ​​support plate 7 increases; motor 12 rotates in reverse → adjustment block 13 moves up → buffer block 5 releases the compression). When the squeegee moves horizontally, the main blade 9 applies the main scraping pressure to the stencil, while the auxiliary blade sleeve 10 adaptively conforms to the template surface. When it encounters a solder resist layer protrusion, the auxiliary blade sleeve 10 slides upward and stores elastic potential energy to avoid solder paste tailing caused by hard scraping. The rubber wear-resistant layer of the buffer block 5 is in rigid contact with the support plate 7, converting the downward pressure transmitted by the adjustment block 13 into uniform surface pressure to prevent pressure fluctuations from affecting the printing quality.

[0031] In practical use, it is necessary to effectively prevent solder paste from overflowing during the printing process. In order to meet the above requirements, baffles 8 are provided at both ends of the bottom wall of the support plate 7 in this embodiment.

[0032] In actual use, it is necessary to ensure the overall toughness of the blade. In order to meet the above requirements, in this embodiment, the main blade 9 is a gradient cemented carbide blade with a diamond-like coating on its cutting edge.

[0033] In actual use, it is necessary to reduce the adhesion rate of solder paste residue and avoid affecting the positioning accuracy due to material accumulation. In order to meet the above requirements, in this embodiment, the outer surface of the baffle 8 is provided with a nano oleophobic coating.

[0034] In actual use, it is necessary to compare the pressure setpoint with the sensor feedback in real time and dynamically correct the output angle of the motor 12. In order to meet the above requirements, in this embodiment, the motor 12 is a closed-loop control step setting.

[0035] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A squeegee for an SMT printing machine, comprising a connecting box (1), characterized in that: The lower end of the connecting box (1) is provided with multiple sets of adjustment components, each of which is provided with a pressure sensor (6). The lower end of the adjustment component is provided with a buffer block (5), the lower end of the buffer block (5) is provided with a support plate (7), the bottom wall of the support plate (7) is provided with a main blade (9), the lower end of the main blade (9) is provided with an auxiliary blade sleeve (10), the auxiliary blade sleeve (10) is adapted to the main blade (9) and is damped and slidably connected, and the upper end of the connecting box (1) is provided with a connecting shaft (2).

2. The SMT printing machine squeegee according to claim 1, characterized in that: The adjustment assembly includes a control box (3), a motor (12), a support rod (4), an adjustment rod (11), and an adjustment block (13). The control box (3) is connected to the connection box (1). The motor (12) is inside the control box (3). The support rod (4) is at the lower end of the motor (12). The adjustment rod (11) passes through the support rod (4) and is connected to the output end of the motor (12). The adjustment block (13) is on the adjustment rod (11) and is threadedly connected to it. The inner sidewall of the support rod (4) is in contact with the adjustment block (13). The buffer block (5) is connected to the bottom wall of the adjustment block (13).

3. The SMT printer squeegee according to claim 1, characterized in that: Both ends of the bottom wall of the support plate (7) are provided with baffles (8).

4. The SMT printing machine squeegee according to claim 1, characterized in that: The pressure sensor (6) is a miniature piezoelectric ceramic sensor.

5. The SMT printer squeegee according to claim 1, characterized in that: The buffer block (5) is a multi-layer composite elastomer structure, including an upper silicone layer, a middle polyurethane honeycomb layer and a lower rubber wear-resistant layer.

6. The SMT printer squeegee according to claim 1, characterized in that: The main blade (9) is a gradient cemented carbide blade with a diamond-like coating on its cutting edge.

7. The SMT printer squeegee according to claim 3, characterized in that: The outer surface of the baffle (8) is provided with a nano-oleophobic coating.

8. The SMT printer squeegee according to claim 2, characterized in that: The motor (12) is a closed-loop control stepper motor.

Images