A scraper assembly and printing device

Abstract

This utility model discloses a squeegee assembly and a printing device. The squeegee assembly includes a squeegee body, a feeding structure, and a pressure sensor. The squeegee body has a closed chamber inside, with a feeding hole on the side wall of the closed chamber and a slit-shaped discharge port at the bottom of the closed chamber. The feeding structure includes a solder paste container and a pressurizing device. A piston is installed inside the solder paste container, forming a sealed space between the piston and the solder paste container. A discharge port is located at the bottom of the sealed space, and the discharge port is connected to the feeding hole via a pipe. The piston is connected to the pressurizing device. The detection end of the pressure sensor extends into the discharge port, and the pressure sensor is electrically connected to the pressurizing device. The printing device includes a squeegee assembly and a lifting assembly for driving the squeegee assembly to rise and fall. In this utility model, the solder paste is located in the closed space inside the squeegee. Printing can be achieved by inputting solder paste through external pressure, and the problem of solder paste being exposed to air is avoided.

Description

Technical Field

[0001] This utility model relates to the field of printing technology, specifically to a doctor blade assembly and a printing device. Background Technology

[0002] During the circuit board manufacturing process, solder paste needs to be applied to the substrate. To achieve this and improve production efficiency, existing printers can design different stencils according to the positions on the substrate where solder paste needs to be applied. During printing, the stencil with pre-drilled holes is first attached to the substrate, and then a squeegee is used to scrape the solder paste exposed to the air into the holes. This solder paste will be accurately printed on various printing positions (such as pads) on the substrate through the mesh of the stencil.

[0003] Traditional chip printers typically use single-blade or double-blade squeegees. In a single-blade configuration, the polyurethane squeegee moves unidirectionally, and the solder paste is placed in the stencil's support area, filling the openings through compression. In a double-blade configuration, the two squeegees move bidirectionally at 120°-150°, with the solder paste stored between the squeegees, alternately applying and replenishing the paste. Both types of solder paste are exposed to air over time, leading to flux evaporation, decreased solder paste fluidity, and resulting in missing corners, bridging, oxidation reactions, hardening, and skinning. This can scratch the stencil, clog micro-openings, requiring machine shutdown for cleaning, and reducing production efficiency. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this utility model provides a squeegee assembly and a printing device. Solder paste is located in the enclosed space inside the squeegee. The solder paste can be input by external pressure to achieve the printing work and avoid the problem of solder paste being exposed to air. It can also increase the filling effect of solder paste. At the same time, compared with the double squeegee structure, it can reduce the cumbersome printing steps and save printing time.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A scraper assembly, comprising:

[0007] The scraper body has a closed chamber inside, the side wall of which is provided with a feed hole, and the bottom of which is provided with a slit-shaped discharge port;

[0008] The feeding structure includes a solder paste container and a pressurizing device. A piston is provided inside the solder paste container, and a sealed space is formed between the piston and the solder paste container. The sealed space is used to store solder paste. A discharge hole is provided at the bottom of the sealed space. The discharge hole is connected to the feed hole through a pipe. The piston is connected to the pressurizing device, and the pressurizing device is used to drive the piston to move within the solder paste container to adjust the size of the sealed space.

[0009] A pressure sensor is installed on the scraper body, and its detection end extends into the discharge port. The pressure sensor is electrically connected to the pressurizing device.

[0010] As a further improvement to the above technical solution, the scraper body includes a lower cavity and an upper cavity. A first groove is provided on the lower cavity. The upper cavity is sealed to the upper cavity and seals the first groove to form the closed chamber. The discharge port is provided at the bottom of the first groove, and the other end of the discharge port passes through the lower cavity.

[0011] As a further improvement to the above technical solution, an extension block is provided at the bottom of the upper cavity, the extension block is connected to the first groove, a second groove is provided at the bottom of the extension block, the second groove is connected to the discharge port, a feed hole is provided on the extension block and connected to the second groove, and a feed pipe connector is provided at the feed end of the feed hole.

[0012] As a further improvement to the above technical solution, a flow divider plate is provided in the first groove, and a plurality of flow divider holes are provided on the flow divider plate. The flow divider holes are located directly above the discharge port and directly below the second groove. The bottom of the flow divider plate abuts against the bottom of the first groove, and the top of the flow divider plate abuts against the bottom of the extension block.

[0013] As a further improvement to the above technical solution, the bottom of the lower cavity is provided with a third groove that is recessed upwards, and the discharge port is located at the top of the third groove.

[0014] As a further improvement to the above technical solution, the scraper body also includes two scraper blades and two scraper blade pressing blocks. The two sides of the lower cavity are set as inclined surfaces oriented towards the discharge port. The two scraper blades are respectively connected to the two inclined surfaces, and the bottom end of the scraper blades extends to the bottom of the third groove. The scraper blade pressing blocks are connected to the lower cavity and press the scraper blades between the inclined surfaces and the scraper blade pressing blocks.

[0015] As a further improvement to the above technical solution, the two ends of the third groove extend through the lower cavity, and the two ends of the lower cavity are provided with solder baffles. The two solder baffles are used to prevent the solder paste in the third groove from flowing out from the two ends of the third groove.

[0016] As a further improvement to the above technical solution, the lower cavity is provided with a mounting hole, the mounting hole is connected to the discharge port, and the pressure sensor is installed in the mounting hole; the tin baffle is provided with a first clearance hole for the feed pipe connector to pass through and a second clearance hole for the pressure sensor to pass through.

[0017] As a further improvement to the above technical solution, the pressurizing device includes an air pump, and a sealing cap is provided at the end of the solder paste container away from the outlet. An air pressure regulating chamber is formed between the sealing cap and the piston. A vent hole is provided on the sealing cap, and the vent hole is connected to the air pump through a pipe. The air pump is used to inject or extract air into the air pressure regulating chamber.

[0018] The technical solution also provided by this utility model is:

[0019] A printing apparatus includes a doctor blade assembly as described above and a lifting assembly for driving the doctor blade assembly to rise and fall. A doctor blade floating mounting plate is provided on the top of the doctor blade body, and the driving end of the lifting assembly is connected to the doctor blade floating mounting plate.

[0020] The beneficial effects of this utility model are:

[0021] 1. Solder paste enters the closed chamber inside the squeegee body from the feeding mechanism and then flows out from the discharge port for printing. Compared with the existing single squeegee or double squeegee structure, it avoids the solder paste being exposed to the air for a long time, thereby improving the printing quality.

[0022] 2. Solder paste flows into the upper cavity through external pressure and then flows evenly into the lower cavity through the flow divider. The groove at the bottom of the lower cavity allows the solder paste to roll during the printing process, ensuring the consistency of the solder paste. At the same time, a pressure sensor is connected to the outlet to detect the pressure inside the closed squeegee in real time.

[0023] 3. Applying solder paste to the main body via external pressure can increase the filling effect of the solder paste. At the same time, compared with the double squeegee structure, it can reduce cumbersome printing steps and save printing time. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is an assembly diagram of a printing device according to an embodiment of the present utility model;

[0026] Figure 2 This is a structural exploded view of a scraper assembly in one direction according to an embodiment of the present invention;

[0027] Figure 3 This is a structural exploded view of a scraper assembly in another direction according to an embodiment of this utility model;

[0028] Figure 4 This is a longitudinal cross-sectional view of a scraper assembly in the left-right direction according to an embodiment of the present utility model;

[0029] Figure 5This is a longitudinal cross-sectional view of a scraper assembly along the front-back direction in an embodiment of this utility model;

[0030] Figure 6 This is a cross-sectional view of the feeding structure in a scraper assembly according to an embodiment of the present invention.

[0031] Reference numerals: 100, scraper body; 110, upper cavity; 111, extension block; 112, second groove; 113, feed hole; 120, lower cavity; 121, first groove; 122, mounting hole; 123, discharge port; 124, third groove; 130, flow divider plate; 131, flow divider hole; 140, scraper blade; 150, scraper blade clamping block; 160, first tin baffle plate; 161, first clearance hole; 170, second tin baffle plate; 171, second clearance hole; 180, feed pipe connector; 200, feed structure; 210, needle tube; 201, sealed space; 202, air pressure regulating chamber; 203, discharge hole; 220, piston; 230, sealing cover; 231, vent hole; 300, pressure sensor; 400, lifting assembly; 500, scraper floating mounting plate. Detailed Implementation

[0032] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / connections involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. For example, fixed connections / fixed installations can use screw connections, bolt connections, pin connections, key connections, adhesive connections, mortise and tenon connections, welding, riveting, etc., as needed. For detachable connections, screw connections, bolt connections, threaded connections, snap-fit ​​connections, mortise and tenon connections, Velcro connections, etc., can be used as needed. The various technical features in this utility model can be combined interactively without contradicting each other.

[0033] Reference Figure 1 This utility model provides a printing device, including a squeegee assembly and a lifting assembly 400. The squeegee assembly includes a squeegee body 100, a feeding structure 200, and a pressure sensor 300. A squeegee floating mounting plate 500 is provided on the top of the squeegee body 100. The driving end of the lifting assembly 400 is connected to the squeegee floating mounting plate 500, thereby driving the squeegee body 100 to move up and down to adjust the distance between the discharge port 123 of the squeegee body 100 and the printing stencil.

[0034] In a specific embodiment, refer to Figures 2-6 The scraper assembly has a closed chamber inside the scraper body 100. The side wall of the closed chamber is provided with a feed hole 113, and the bottom of the closed chamber is provided with a slit-shaped discharge port 123. The feed structure 200 of the scraper assembly includes a solder paste container and a pressurizing device. A piston 220 is provided inside the solder paste container, and a sealed space 201 is formed between the piston 220 and the solder paste container. The sealed space 201 is used to store solder paste. The bottom of the sealed space 201 is provided with a discharge hole 203. The discharge hole 203 is connected to the feed hole 113 through a pipe. The piston 220 is connected to the pressurizing device, and the pressurizing device is used to drive the piston 220 to move in the solder paste container to adjust the size of the sealed space 201. When the pressurizing device drives the piston 220 to move downward, it forces the solder paste to flow out from the outlet 203, enter the closed chamber through the inlet 113 via the pipe, and then flow out from the outlet 123 for printing.

[0035] Furthermore, the scraper body 100 is equipped with a pressure sensor 300, and its detection end extends into the discharge port 123. The pressure sensor 300 is electrically connected to the pressurizing device, thus forming a closed-loop control. The pressure sensor 300 detects the pressure of the solder paste in the discharge port 123 in real time, thereby controlling the pressure of the pressurizing device on the piston 220 to adjust the size of the sealed space 201, that is, to adjust the output amount of solder paste.

[0036] In this embodiment, refer to Figures 2-5 The scraper body 100 includes a lower cavity 120 and an upper cavity 110. The lower cavity 120 is provided with a first groove 121, and the bottom of the first groove 121 is provided with a discharge port 123. The other end of the discharge port 123 passes through the lower cavity 120. The upper cavity 110 is sealed to the first groove 121 to form the closed chamber. Specifically, the bottom of the upper cavity 110 is provided with an extension block 111, which is connected to the first groove 121. The bottom of the extension block 111 is concave upward with a second groove 112 with an arc-shaped cross-section. The second groove 112 communicates with the discharge port 123. The extension block 111 is provided with a feed hole 113 that communicates with the second groove 112. The end of the feed hole 113 away from the second groove 112 is provided with a feed pipe connector 180. With the above settings, the solder paste enters the second groove 112 directly from the feed hole 113 into the discharge port 123, which improves the flow efficiency of the solder paste, ensures that the solder paste can be filled quickly, and guarantees the printing operation.

[0037] Preferred, refer to Figures 2-5 A flow divider plate 130 is provided within the first groove 121. The flow divider plate 130 has a plurality of flow divider holes 131, which are located directly above the outlet 123 and directly below the second groove 112. Solder paste flows evenly from the second groove 112 through the flow divider holes 131 into the outlet 123, ensuring consistency of solder paste during printing. The bottom of the flow divider plate 130 abuts against the bottom of the first groove 121, and the top of the flow divider plate 130 abuts against the bottom of the extension block 111, thereby ensuring that solder paste enters the outlet 123 from the second groove 112 through the flow divider holes 131, preventing solder paste from leaking out from the top and bottom sides of the flow divider plate 130.

[0038] Furthermore, refer to the figure. Figures 3-5 The bottom of the lower cavity 120 is recessed upward with a third groove 124 having an arc-shaped cross-section. The discharge port 123 is located at the top of the third groove 124. Solder paste flows evenly into the discharge port 123 through the diverter plate 130 and then into the third groove 124, which enables the solder paste to roll during the printing process and ensures the consistency of the solder paste.

[0039] In some embodiments, refer to Figure 2 , Figure 3 or Figure 5 The squeegee body 100 also includes two squeegee blades 140 and two squeegee blade pressing blocks 150. The two sides of the lower cavity 120 are configured as inclined surfaces oriented towards the discharge port 123. The two squeegee blades 140 are respectively connected to the two inclined surfaces, and the bottom end of the squeegee blades 140 extends to the bottom of the third groove 124. The squeegee blade pressing blocks 150 are connected to the lower cavity 120 and press the squeegee blades 140 between the inclined surfaces and the squeegee blade pressing blocks 150. In this way, the solder paste is scraped by the squeegee blades 140 during the printing operation, thereby improving the printing effect.

[0040] In some embodiments, refer to Figures 2-4 The two ends of the third groove 124 extend through the lower cavity 120. The two ends of the lower cavity 120 are provided with a first tin-blocking plate 160 and a second tin-blocking plate 170. The first tin-blocking plate 160 and the second tin-blocking plate 170 are respectively used to prevent the solder paste in the third groove 124 from flowing out from the two ends of the third groove 124, thereby ensuring that the solder paste remains in the third groove 124 during the printing operation.

[0041] The lower cavity 120 is provided with a mounting hole 122, which is connected to the discharge port 123. The pressure sensor 300 is installed in the mounting hole 122, so that the detection end of the pressure sensor 300 is located in the discharge port 123 to detect the pressure of the solder paste in the discharge port 123.

[0042] The first tin-blocking plate 160 is provided with a first clearance hole 161 for the pressure sensor 300 to pass through, and the second tin-blocking plate 170 is provided with a second clearance hole 171 for the feed pipe connector 180 to pass through, which facilitates the assembly of the scraper assembly.

[0043] In this embodiment, refer to Figure 6 The pressurizing device includes an air pump (not shown in the figure), and the solder paste container is a needle tube 210. A sealing cap 230 is provided at the end of the needle tube 210 away from the discharge port 203. An air pressure regulating chamber 202 is formed between the sealing cap 230 and the piston 220. A vent hole 231 is provided on the sealing cap 230. The vent hole 231 is connected to the air pump through a pipe. Air is injected into the air pressure regulating chamber 202 by the air pump, and the air pressure in the air pressure regulating chamber 202 increases, thereby forcing the piston 220 to move downward to realize the input of solder paste. In addition, air is pumped out of the air pressure regulating chamber 202 by the air pump, and the air pressure in the air pressure regulating chamber 202 decreases, thereby forcing the piston 220 to move upward, which can draw the solder paste back into the needle tube 210. By using the closed-loop control of the pressure sensor 300 and the air pump, the pressure of the solder paste at the outlet 123 is detected in real time, thereby adjusting the air pressure in the air pressure regulating chamber 202 to control the input amount of solder paste, ensuring printing consistency and improving printing quality.

[0044] The above is a detailed description of the preferred embodiments of the present utility model. However, the present utility model is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present utility model. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A scraper assembly, characterized in that, include: The scraper body has a closed chamber inside, the side wall of which is provided with a feed hole, and the bottom of which is provided with a slit-shaped discharge port; The feeding structure includes a solder paste container and a pressurizing device. A piston is installed inside the solder paste container, and a sealed space is formed between the piston and the solder paste container. The sealed space is used to store solder paste. A discharge hole is provided at the bottom of the sealed space. The discharge hole is connected to the feed hole through a pipe. The piston is connected to the pressurizing device, and the pressurizing device is used to drive the piston to move within the solder paste container to adjust the size of the sealed space. A pressure sensor is installed on the scraper body, and its detection end extends into the discharge port. The pressure sensor is electrically connected to the pressurizing device.

2. The scraper assembly according to claim 1, characterized in that: The scraper body includes a lower cavity and an upper cavity. A first groove is provided on the lower cavity. The upper cavity is sealed to the upper cavity and seals the first groove to form the closed chamber. The discharge port is provided at the bottom of the first groove, and the other end of the discharge port passes through the lower cavity.

3. A scraper assembly according to claim 2, characterized in that: The bottom of the upper cavity is provided with an extension block, which is connected to the first groove. The bottom of the extension block is provided with a second groove, which is connected to the discharge port. The extension block is provided with a feed hole that is connected to the second groove, and the feed end of the feed hole is provided with a feed pipe connector.

4. A scraper assembly according to claim 3, characterized in that: A flow divider plate is provided in the first groove, and a plurality of flow divider holes are provided on the flow divider plate. The flow divider holes are located directly above the discharge port and directly below the second groove. The bottom of the flow divider plate abuts against the bottom of the first groove, and the top of the flow divider plate abuts against the bottom of the extension block.

5. A scraper assembly according to claim 3, characterized in that: The bottom of the lower cavity is recessed upwards with a third groove, and the discharge port is located at the top of the third groove.

6. A scraper assembly according to claim 5, characterized in that: The scraper body also includes two scraper blades and two scraper blade pressing blocks. The two sides of the lower cavity are set as inclined surfaces oriented towards the discharge port. The two scraper blades are respectively connected to the two inclined surfaces, and the bottom end of the scraper blades extends to the bottom of the third groove. The scraper blade pressing blocks are connected to the lower cavity and press the scraper blades between the inclined surfaces and the scraper blade pressing blocks.

7. A scraper assembly according to claim 6, characterized in that: The two ends of the third groove extend through the lower cavity, and the two ends of the lower cavity are provided with solder baffles. The two solder baffles are used to prevent the solder paste in the third groove from flowing out from the two ends of the third groove.

8. A scraper assembly according to claim 7, characterized in that: The lower cavity is provided with a mounting hole, which is connected to the discharge port. The pressure sensor is installed in the mounting hole. The tin baffle is provided with a first clearance hole for the feed pipe connector to pass through and a second clearance hole for the pressure sensor to pass through.

9. A scraper assembly according to claim 1, characterized in that: The pressurizing device includes an air pump. A sealing cap is provided at the end of the solder paste container away from the outlet. An air pressure regulating chamber is formed between the sealing cap and the piston. A vent is provided on the sealing cap. The vent is connected to the air pump through a pipe. The air pump is used to inject or extract air into the air pressure regulating chamber.

10. A printing apparatus, characterized in that: The invention includes the scraper assembly as described in any one of claims 1-9 and a lifting assembly for driving the scraper assembly to rise and fall, wherein a scraper floating mounting plate is provided on the top of the scraper body, and the driving end of the lifting assembly is connected to the scraper floating mounting plate.

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