A sealed squeegee that can supply solder paste at a uniform density

Abstract

To provide a sealed squeegee capable of supplying a solder paste with a uniform density.SOLUTION: A sealed squeegee capable of supplying a solder paste with a uniform density comprises a chamber housing 100, a solder mixing unit, a squeegee blade holder, a holding and placing unit 400, a pumping coupling unit, a chamber sealing cover 600, a side cover 800, and a cover holding member 900.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a closed type squeegee capable of supplying solder paste at a uniform density. More specifically, the present invention relates to a closed type squeegee capable of supplying solder paste at a uniform density during screen printing, thereby improving the screen printing quality of printed circuit boards, thereby minimizing product defects, minimizing the amount of solder paste remaining after solder paste supply, thereby reducing raw material waste, and minimizing printing defects by shortening cleaning time due to simplified components, as printing is possible without mixing different types of solder creams, and minimizing the printing defect rate. The closed type squeegee ensures density constancy during solder supply through improved sealing force and cross pumping that expands and contracts with compressed air, and can simultaneously pressurize and discharge a large amount of solder instead of locally pressing on the same line. [Background technology]

[0002] Generally, a molten solder paste is printed in a certain pattern on a printed circuit board (PCB), which is built into electronic devices such as computers and home appliances as a main component, so that various types of electronic components such as semiconductor chips and resistor chips can be mounted on the printed circuit board. The solder paste printing process is performed by a screen printer, which applies the solder paste supplied onto a metal mask with openings of a specific pattern by pressing the solder paste with a squeegee and then applying it to the component mounting portion of the printed circuit board.

[0003] Fig. 1 is a schematic diagram showing the inside of an example of a solder pump. Referring to Fig. 1, the solder pump 10 is mounted on a screen printer for injecting solder paste onto a mask, and includes a first chamber 13, a second chamber 14, a first pressure plate 15, a first pressure rod 11, a second pressure plate 16, a second pressure rod 12, and a nozzle unit 18.

[0004] The inside of the solder pump 10 is divided into a first chamber 13 and a second chamber 14, and the first chamber and the second chamber contain solder paste, respectively. The first pressure plate 15 moves back and forth inside the first chamber and contacts the solder paste contained in the first chamber. A first pressure rod is connected to the first pressure plate 15, and a drive unit is usually connected to the first pressure rod to apply pressure to the solder paste contained in the first chamber. Similarly, the second pressure plate 16 moves back and forth inside the second chamber and contacts the solder paste contained in the second chamber. A second pressure rod is connected to the second pressure plate 16, and a drive unit is usually connected to the second pressure rod to apply pressure to the solder paste contained in the second chamber. The first pressure rod 11 and the second pressure rod 12 repeatedly rise and fall, so that the solder paste contained in the first chamber and the second chamber is sprayed onto the mask through the nozzle unit 18.

[0005] 1 is designed to supply solder paste of uniform quality and minimize the amount of wasted solder paste by alternately pressurizing the solder paste contained in two different chambers and spraying it onto a mask, but it does not work that way. The reason is that when the first chamber 13 side is pressurized by the first pressure plate 15, the solder paste is discharged through the nozzle part 18, but the pressure change on the second pressure plate 16 side becomes irregular as the solder paste on the nozzle part side flows, and the discharge density of the solder paste discharged through the nozzle part 18 also becomes irregular.

[0006] Therefore, in the solder paste printing process, there is a problem that the solder paste has a non-uniform quality, which causes poor mounting of electronic components on a printed circuit board. In addition, after the process is completed, the remaining solder paste in the solder pump causes poor cleaning, and since it is impossible to completely clean the remaining solder paste, when a different type of solder paste is introduced, it not only causes poor purity of the solder paste and thus poor printing, but also causes cost waste due to the remaining expensive solder paste.

[0007] Meanwhile, FIG. 2 discloses a conventional solder paste supplying device. In this device, a first chamber and a second chamber are formed symmetrically, and a bottleneck connecting part connecting the first chamber and the second chamber is formed in a "V" shape. A first pressurizing part and a second pressurizing part are formed symmetrically on one side of the first chamber and the second chamber, respectively. A nozzle part is formed at the bottleneck connecting part. This conventional solder paste supplying device is also configured to pressurize the solder paste contained in each chamber and move it to the bottleneck connecting part by operating the first pressurizing part and the second pressurizing part provided on the left and right sides, and discharge the solder paste to the nozzle part of the bottleneck connecting part. Here, the pressure on the nozzle part side is increased more than the pressure of each chamber through the bottleneck connecting part, thereby compensating for the pressure drop when the solder paste is discharged through the nozzle part, and the solder paste is discharged uniformly.

[0008] However, this is merely a bottleneck connection part configuration in which the section is narrowed, and when the initial solder paste is sufficient, the solder paste can be discharged at a uniform density, but when the remaining amount of solder paste is insufficient, it is difficult to compensate for the pressure at the bottleneck connection part, so the solder paste is discharged at an uneven density, which ultimately leads to printing defects and product defects. Furthermore, in order to compensate for the pressure drop at the bottleneck connection part of this conventional solder paste supplying device, a blocking plate for blocking a part of the cross section is formed, but this also makes it difficult to compensate for the pressure when the remaining amount of solder paste is small, and instead interferes with the section where the solder paste is discharged through the nozzle part, resulting in uneven discharging of the solder paste.

[0009] As an example of a solder paste supplying apparatus that has been disclosed recently to solve the above problems, as shown in FIG. 3, Korean Patent No. 10-1658406 discloses a solder paste supplying apparatus that maintains a constant pressure in a chamber containing the solder paste and minimizes pressure changes in the chamber by buffering pressure shocks that may occur when pressurizing the chamber by a pressurizing means so that the solder paste can be more stably discharged at a uniform density, and that continuously compensates for pressure drops in the nozzle portion, thereby supplying solder paste to correspond to patterns formed on a mask in order to mount various electronic components on a printed circuit board, and that adjusts the solder paste to a uniform density during screen printing so that the solder paste can be supplied at the same density at all times, thereby improving printing quality and minimizing product defects, and minimizing the amount of solder paste remaining after supplying the solder paste, thereby reducing waste of raw materials.

[0010] The uniform density solder paste supplying device is configured such that solder is filled into a buffer storage section formed to be long in the length direction, and the filled solder is discharged by pressure through a nozzle section on a lower side having the same length as the length of the buffer storage section. The pressurizing means pressurizes and releases the solder paste supplied through the solder paste supplying section as it reciprocates through a pressurizing chamber so that the solder is filled into the buffer storage section. Correspondingly, the buffer adjusting means is configured to buffer the solder paste as it reciprocates within the pressure buffer adjusting chamber by the pressure applied and released by the pressurizing means, and the solder paste is discharged through the nozzle section with uniform pressure and uniform density.

[0011] However, since the pressurizing chambers and the pressure buffer adjusting chambers of the solder paste uniform density supplying device are formed at equal intervals and the pressurizing means and the buffer adjusting means are locally coupled to each of the pressurizing chambers and the pressure buffer adjusting chambers, localized pressurization and release of the solder paste filled in the buffer receiving portion formed long in the length direction occurs, making it difficult to mix the solder paste at a uniform density, and since a vacuum is applied to each chamber during the process of pressurizing and releasing by the pressurizing means and the buffer adjusting means with the solder paste filled, the solder paste is not uniformly distributed throughout the buffer receiving portion, causing a problem that the solder paste applied to the mask is not uniformly supplied, which causes printing defects since the solder paste is not properly supplied to the mask. That is, by configuring a large number of pressurizing chambers and pressure buffer adjusting chambers, there are problems in that pressure is not applied between each chamber, and that each chamber acts locally on the solder paste, making it difficult to mix the solder paste at a uniform density. Furthermore, when the solder paste is filled in the buffer storage section, a vacuum is generated in each chamber, making it difficult to easily exhaust the internal air, resulting in non-uniform density of the solder paste.

[0012] In addition, disassembly and assembly becomes difficult due to the multiple pressurizing means and pressure buffer adjustment chambers, and when different types of solder paste are used, the solder paste is not easily removed during the cleaning process to replace it, which causes problems such as poor cleanability.If the cleanability is poor as described above and solder paste remains in each chamber, the different types of solder paste will be diluted with each other, resulting in product defects.

[0013] Furthermore, as mentioned above, since multiple pressure means act locally, pressure changes occur depending on the position of the pressure means, and it is difficult to apply the same pressure, making it difficult to mix the solder paste and, as a result, to supply the solder paste with a uniform density. Such pressure changes act as a factor that hinders smooth mixing of the solder paste, since the air contained in the chamber cannot escape to the outside due to the application of a vacuum.

[0014] Meanwhile, in terms of the above-mentioned cleanability, since a large number of pressurizing means and buffer adjusting means are formed, and a large number of pressurizing chambers and pressure buffer adjusting chambers are also formed correspondingly, disassembly and assembly are difficult, and cleaning after supplying and using solder paste is not easy. There is a problem that all components connected to each chamber must be released for cleaning, and there is also a problem that considerable care must be taken when cleaning since there is a risk of losing each part during the cleaning process since there are a large number of parts.

[0015] Due to the reduced ease of cleaning, as mentioned above, when two or more types of solder creams are used separately, the solder creams are diluted and mixed, making it difficult to ensure uniformity and consistency of product quality and resulting in a large number of defective products.

[0016] In addition, even if multiple chambers are disassembled and reassembled, it is difficult to reassemble them so that the initial sealing force is maintained during the reassembly process. Therefore, it is only possible to check whether each part is precisely assembled while maintaining the sealing force by checking the production process of the product after assembly. If a joint shows poor sealing force, it is difficult to check in which part and how the sealing force is not being maintained, so it is necessary to disassemble and reassemble the entire unit, which is troublesome.

[0017] Furthermore, if different pressures are applied to each chamber, it is not easy to stir the solder paste, and although it is possible to obtain a substantially uniform density of the solder paste, there may be sections where the solder paste is not obtained at a uniform density due to pressure loss at certain locations. That is, currently disclosed solder paste uniform density devices obtain a uniform density of the solder paste by maintaining a uniform pressure within the chambers, buffering pressure shocks, and minimizing pressure changes, but due to the various problems mentioned above, there is a demand for a solder paste uniform density device that solves the above problems.

[0018] That is, cleaning must be performed to prevent the mixing and dilution of different solder creams, which is the most critical problem among the above problems. However, currently disclosed uniform density solder paste apparatuses have significantly reduced cleanability, and the mixing and dilution of different solder creams frequently occurs, resulting in defective products. Therefore, a uniform density solder paste apparatus with improved cleanability is required. A uniform density solder paste supplying apparatus with improved cleanability has been recently disclosed to meet such a requirement, as described in Korean Patent Registration No. 10-2100515. The uniform density supplying apparatus includes a cylinder housing 10 having an injection port 11, a cylinder mounting portion 13, and a guide mounting portion 14, a pressure buffer cylinder 20, a piston head, a solder basket 40, a divider member, a side cover 60, a squeegee blade holder, a guide housing 80, and a guide shaft 90, as shown in FIG. 4.

[0019] In consideration of this, the inner space of the solder basket, which has a space with an inverted triangular cross section formed in the length direction, is divided into each compartment by a divider member, and a cylinder housing is airtightly coupled to the upper part of the solder basket. Before airtight coupling, a pressure buffer cylinder is coupled to the upper part of the cylinder housing, and a piston head is coupled to the end of the cylinder rod with a length corresponding to the left and right spaces of the solder basket divided by the divider member. The uniform density supply device coupled as above has a similar operation state of mixing the solder paste so that the density of the solder paste is uniform as in the uniform density supply device of the solder paste described above, but in terms of improving the cleaning performance, which is the most important point, the piston head for pressurization and buffering has a shape corresponding to the length direction of the left and right interiors of the solder basket where the solder paste is supplied and discharged, making it easy to disassemble and assemble. In addition, since the inverted triangular inner space of the solder basket is configured to be divided into left and right compartments by the divider member, the inner space of the solder basket is completely opened by simply disassembling the divider member, which allows for easy disassembly and assembly, and cleaning can be easily performed.

[0020] Therefore, the existing cleanability problem was solved by simplifying the parts, but when the solder paste is supplied to the portion divided by the divider member and mixed by pressurization and buffering, the divider member does not maintain airtightness, and the left and right spaces are connected to each other, which causes problems when mixing the solder paste at a uniform density and leads to printing defects. Furthermore, the piston rod presses and buffers the pressure due to the action of the pressurization buffer cylinder, but the piston rod itself is long, which causes uneven pressure distribution and local pressure where pressure is applied only to certain parts, which causes a new problem in that it is difficult to mix the solder paste at a uniform density due to the buffering problem.

[0021] Furthermore, if the pressure and buffer capacity of the pressure buffer cylinder are not the same, this effect becomes even more severe, and because the piston rod is long in both the front and back, when a front pressure of 10 is applied, the rear pressure is increased by 8 to 9 due to the difference in the front and back pressures like a seesaw, and as a result, the piston rod is not pressed while maintaining the same horizontal state, but is pressed while tilted like a seesaw, which causes the problem that the solder paste is not mixed smoothly with a uniform density. That is, although the problem of mixing different types of solder paste has been solved by improving the cleanability, if the difference in pressure during the operation causes local pressure changes and the front and back are no longer pressed with the same pressure, the piston rod itself will malfunction in its up and down operation, causing damage or breakage to the uniform density supply device for solder paste, and the piston rod will communicate with each other during the up and down operation of the piston rod, causing pressure leakage, resulting in printing defects. [Prior art documents] [Patent documents]

[0022] [Patent Document 1] Korean Patent No. 10-1356562 [Patent Document 2] Korean Patent No. 10-1196284 [Patent Document 3] Korean Patent No. 10-1658406 [Patent Document 4] Korean Patent No. 10-2100515 Summary of the Invention [Problem to be solved by the invention]

[0023] Therefore, the present invention has been made to solve the above-mentioned problems, and has an object to provide a closed squeegee capable of supplying solder paste at a uniform density, which minimizes poor connection of parts by unifying a pressure buffer adjustment chamber and a pressurizing means and buffer adjustment means coupled thereto, thereby reducing the number of parts, and improving sealing force, easily applying and buffering pressure uniformly, quickly discharging internal air to the outside in front of and behind the pressure chamber, and mixing the solder paste at a uniform density in the pressure chamber or filling it without voids, thereby discharging the solder paste for printing at a uniform density.

[0024] In addition, the present invention aims to provide a closed type squeegee capable of supplying paste at a uniform density, which is configured to mix solder paste at a uniform pressure in a pressure chamber, which is a component of a conventional solder paste uniform density supplying device, and which simplifies parts by unifying a pressure buffer adjustment chamber, a pressure means, and a buffer adjustment means, thereby improving ease of disassembly and assembly and cleanability, and allowing cleaning without residue of solder paste once used, thereby preventing mixing between the remaining solder paste and the newly added solder paste when replacing with another type of solder paste, improving sealing force, and simultaneously pressurizing a large amount of solder along the length direction of the pressure chamber during one pumping process, thereby allowing solder paste to be quickly formed at a uniform density through a fast mixing time.

[0025] Another object of the present invention is to provide a closed squeegee capable of supplying solder paste at a uniform density, in which the partitioned pressurizing means in which the solder paste is stored, the solder buffer storing portion, and the pressure buffer adjusting chamber are unified into a single pumping pad configuration, thereby always maintaining a constant pressure inside the front and rear and more stably discharging the solder paste at a uniform density. The pumping pad that can be expanded by air buffers pressure shock that may be generated by the pressure applied to the pressurizing chamber, minimizes pressure changes in the pressurizing chamber, and continuously compensates for pressure drops in the nozzle portion, thereby adjusting the solder paste to a uniform density and always supplying solder paste at the same density. The uniform solder paste improves printing quality and minimizes product defects, and minimizes waste of raw materials by minimizing the amount of solder paste remaining after the solder paste is supplied. [Means for solving the problem]

[0026] In order to achieve the above object, the present invention provides a closed squeegee capable of supplying solder paste at a uniform density, comprising: a chamber housing 100 formed long in a direction intersecting a direction in which the squeegee of a screen printer moves, for supplying solder paste to a mask at a uniform density; a solder mixing unit 200 having a V-shaped cross section on the left and right sides of a cross section perpendicular to the longitudinal direction of the chamber housing 100 so that the solder paste is uniformly mixed through pressure application and pressure buffering, a pressure chamber 210 formed penetrating the length of the chamber housing, and a nozzle unit 220 formed at a lower surface of the pressure chamber 210 through which the solder paste supplied, received, and uniformly mixed in the pressure chamber 210 is discharged to the outside; and a solder mixing unit 200 coupled to the front and rear of the lower side of the chamber housing 100, and configured to mix the solder paste when the solder paste is supplied onto the mask. a holding mounting part 400 having front and rear vertical faces 402 protruding from the upper side of the chamber housing 100 and a mounting horizontal face 404 formed in a left and right length direction and having at least one solder injection hole 406 formed on an upper face thereof, the solder paste being supplied from the outside and injected into the pressure chamber 210; a pumping coupling part 500 having pumping through holes 510 communicating with the pressure chamber 210 symmetrically formed on the front and rear faces in the length direction of the chamber housing 100, having sealed coupling grooves 520 formed on the front and rear faces of the chamber housing 100 outside the inner periphery of the pumping through holes 510, and having a hinge coupling device 530 protruding from the lower side of the sealed coupling grooves 520;The chamber sealing cover 600 is formed as a rectangular plate having a length corresponding to the length in the left and right directions of the chamber housing 100 so as to cover the pumping coupling part 500 so as not to be exposed to the outside, and a hinge coupling piece 610 is formed on the lower side of the rectangular plate to be hingedly coupled to the hinge coupling device 530, and is provided to cover the pumping coupling part 500 by rotating, and has a number of air injection holes 620 formed on the outer surface so that compressed air is supplied to and discharged from the pumping through-hole 510 side of the pumping coupling part 500, and is formed symmetrically in the front and rear; The chamber sealing cover 600 is airtightly coupled to the sealing coupling groove 520 while blocking the pumping through-hole 510 formed in the pumping coupling part 500, and is formed so as to maintain airtight coupling with the pumping coupling part 500 when the chamber sealing cover 600 rotates toward the holding placement part 400, and the pumping through-hole 510 is filled with compressed air supplied and discharged through the number of air injection holes. 0, and pumping pad 700 which pumps the solder paste contained in the pressure chamber by repeatedly expanding and contracting inwardly of pressure chamber 210 which is connected to the left and right sides of chamber housing 100 so as to be sealed, side cover 800 formed with air vent 810 passing therethrough so that the air inside pressure chamber 210 of chamber housing 100 is exhausted and the inflow of external air is blocked; cover holding member 900 formed long in the left and right length direction, coupled to horizontal mounting surface 404 so as to restrict the rotation of chamber sealing cover 600 which rotates toward holding mounting part 400, and provided with supply through hole 902 which supplies solder paste while communicating with solder injection port 406 formed on horizontal mounting surface 404.

[0027] Here, when compressed air is supplied through the air injection hole 620 of the chamber sealing cover 600 formed on the left side of the cross section, the pumping pad 700 coupled to the sealing coupling groove 520 expands into the pressure chamber 210 on the left side of the “V” shaped cross section while blocking the pumping through hole 510, thereby pressurizing and mixing the solder paste contained inside the pressure chamber, and during the pressurization process, the pressure shock caused by the expansion pressure of the pumping pad passes through the pressure chamber 210 on the right side of the “V” shaped cross section, and the pumping pad 700 deforms into the inner surface of the chamber sealing cover on the pumping through hole 510 side to buffer it, thereby uniformly mixing the solder paste. When the left side of the pressure chamber 210 is pressurized, the right side buffers the pressure shock inside the pressure chamber 210, and when the right side is pressurized, the left side buffers the pressure shock inside the pressure chamber 210.

[0028] Meanwhile, a closing surface 630 is formed at an end of the chamber sealing cover 600 opposite to the end where the hinge connection piece 610 is formed, the closing surface 630 being in contact with the vertical surface 402 of the holding mounting part 400, and a holding surface 640 is formed perpendicular to the closing surface 630 and in the same plane as the mounting horizontal surface 404, and the holding surface 640 is formed such that the closing surface 630 is in contact with the vertical surface 402 and in the same horizontal plane as the mounting horizontal surface 404, and then, as the cover holding member 900 is coupled to the mounting horizontal surface 404, the lower surface of the cover holding member 900 presses the holding surface 640 to control a rotation operation for opening the chamber sealing cover 600.

[0029] Here, the front-to-rear width of the cover holding member 900 is formed smaller or larger than the width at which the mounting horizontal surface 404 and the holding surface 640 are flush with each other as the chamber sealing cover 600 rotates to the holding mounting part 400, and it is also preferable that the width is larger than the width of the mounting horizontal surface 404.

[0030] Meanwhile, the pumping pad 700 pumps by repeatedly expanding and contracting in the pressurized chamber 210 and the pumping through-hole 510 due to the pressure of compressed air supplied through a plurality of air injection holes 620 formed in the chamber sealing cover 600, and includes a sealing part 710 formed to a length corresponding to a length capable of sealing the pumping through-hole 510 and airtightly coupled to the sealing coupling groove 520 formed on the inner periphery of the pumping through-hole 510; and a pressure buffer part 720 extended from the sealing part 710 and recessed from the pumping through-hole 510 into the pressurized chamber 210, and configured to expand toward the pressurized chamber 210 due to the compressed air supplied through a plurality of air injection holes 620 formed in the chamber sealing cover 600, or to contract and buffer due to the pressure shock in the pressurized chamber 210, so that the solder paste in the pressurized chamber is uniformly mixed.

[0031] In addition, a buffer expansion / contraction part 722 is further formed in the center of the pressurizing buffer part so as to be elongated in the length direction and recessed from the pressurizing chamber to the pumping through-hole side, so that the expansion of the pressurizing buffer part 720 further expands into the pressurizing chamber 210 to pressurize the solder paste, and the pressure shock in the pressurizing chamber due to the pressurization is buffered by quickly contracting, and it is also preferable that the overall cross section of the pressurizing buffer part and the buffer expansion / contraction part be formed in a “W” shape.

[0032] Meanwhile, the buffer expansion / contraction part 722 is recessed toward the pressurizing chamber 210 at the center thereof with a length corresponding to the length of the pumping through-hole 510, and a sub-pressurizing buffer part 724 is further formed in the buffer expansion / contraction part so that the buffer expansion / contraction part can easily expand toward the pressurizing chamber by compressed air, and the entire cross section is formed to include a wrinkled cross section.

[0033] Meanwhile, the pumping pad 700 is made of any one of rubber or synthetic rubber, elastic synthetic resin, and silicone, which can expand and contract while having elasticity to return to its original state. Effect of the Invention

[0034] The present invention unifies the pressure buffer adjustment chamber and the correspondingly coupled pressurizing means and buffer adjustment means into one pumping pad configuration, thereby reducing the number of parts, thereby minimizing poor sealing force due to the coupling of parts and improving sealing force, uniform pressurization and buffering of pressure are easily performed, internal air is quickly discharged to the outside on the left and right sides of the pressurization chamber, and the solder paste is mixed in the pressurization chamber at a uniform density or filled without voids, so that the solder paste for printing can be discharged at a uniform density, and the solder paste is mixed in the pressurization chamber at a uniform pressure, which is a configuration in which the solder paste is mixed at a uniform density. The pressure buffer adjustment chamber, the pressurizing means, and the buffer adjustment means are integrated into the pumping pad configuration, simplifying the components, thereby improving ease of disassembly and assembly and cleaning. It is possible to clean without leaving any residue of solder paste once used. Therefore, when replacing with another type of solder paste, there is no mixing between the remaining solder paste and the newly added solder paste, minimizing the defect rate and improving sealing force. In addition, a large amount of solder is simultaneously pressurized along the length of the pressurizing chamber in one pumping process, so that the solder paste can be quickly formed with uniform density through a fast mixing time.

[0035] In addition, the present invention has an advantage in that the partitioned pressurizing means in which the solder paste is accommodated, the solder buffer accommodation portion, and the pressure buffer adjusting chamber are integrated into one pumping pad, so that the pressure inside the front and rear can be constantly maintained constant and the solder paste can be more stably discharged at a uniform density. The pumping pad, which can be expanded by air pressure, buffers pressure shock that may be generated by pressure applied to the pressurizing chamber, minimizes pressure changes within the pressurizing chamber, and continuously compensates for pressure drops in the nozzle portion, thereby adjusting the solder paste to a uniform density and always supplying the solder paste at the same density. The uniform solder paste improves printing quality and minimizes product defects. It also has the advantage in that the amount of solder paste remaining after supplying the solder paste can be minimized, thereby reducing waste of raw materials. [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is a diagram showing an example of a conventional solder paste pump coupled with a squeegee. [Diagram 2] FIG. 1 is a diagram showing an example of a conventional solder paste supplying device coupled with a squeegee. [Diagram 3] 1 is an overall perspective view of a conventional solder paste uniform density supplying device combined with a squeegee; [Figure 4] 1 is an overall perspective view of a conventional solder paste uniform density supplying device combined with a squeegee and improving cleanability; [Diagram 5] 1 is an overall perspective view of a closed-type squeegee capable of supplying solder paste according to the present invention at a uniform density. [Figure 6] 1 is an exploded perspective view of a closed-type squeegee capable of supplying solder paste at a uniform density according to the present invention. [Figure 7] 1 is a perspective view of a chamber housing of a sealed squeegee capable of dispensing solder paste at a uniform density according to the present invention. FIG. [Figure 8] 1 is a side cross-sectional view showing an operation state of a closed-type squeegee capable of supplying solder paste at a uniform density according to the present invention. [Figure 9] 9 is an enlarged view of a main portion of the enclosed squeegee according to the present invention, showing the operation of the pumping pad of FIG. 8, which is capable of supplying solder paste at a uniform density. [Figure 10] 11 is a side cross-sectional view showing an operation state of another embodiment of a closed-type squeegee capable of supplying solder paste at a uniform density according to the present invention. FIG. [Figure 11] 11 is an enlarged view of a main portion of the enclosed squeegee according to the present invention, showing the operation of the pumping pad of FIG. 10, which is capable of supplying solder paste at a uniform density. [Figure 12] 11 is a side cross-sectional view showing the operation of yet another embodiment of a closed-type squeegee capable of supplying solder paste at a uniform density according to the present invention. FIG. [Figure 13] 13 is an enlarged view of a main portion of the enclosed squeegee according to the present invention, showing the operation of the pumping pad of FIG. 12, which is capable of supplying solder paste at a uniform density. [Figure 14] 2 is a partially cutaway perspective view showing a state before a pumping pad of a closed-type squeegee capable of supplying solder paste at a uniform density according to the present invention is bonded; FIG. [Figure 15] 1 is a partially cutaway perspective view showing an operating state of a chamber sealing cover after a pumping pad of a sealed squeegee capable of supplying solder paste at a uniform density according to the present invention is coupled; FIG. [Figure 16] 1 is a partially cutaway perspective view showing a state after a pumping pad of a sealed squeegee capable of supplying solder paste at a uniform density according to the present invention is coupled to a chamber sealing cover and before a cover holding member is coupled thereto; [Figure 17] 1 is a partially cutaway perspective view showing a coupled state of a cover holding member of a closed type squeegee capable of supplying solder paste at a uniform density according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, technical features of an embodiment of the apparatus for supplying solder paste at a uniform density according to the present invention will be described in detail with reference to the accompanying drawings.

[0038] As described above, the sealed squeegee capable of supplying solder paste at a uniform density according to the present invention does not require a separate structure for pressurization and buffering compared to a squeegee equipped with a conventional solder paste uniform density supply device. Instead, the solder paste can be uniformly mixed in the pressurized chamber with a single structure of one pumping pad. The simplified components ensure ease of disassembly and assembly and cleaning. Due to the characteristics of the pumping pad for pressurization and buffering, the cost is low, making it more economical. Furthermore, pressure can be applied uniformly when pressure is applied due to expansion and contraction through a uniform inflow of compressed air, and pressure is not limited to a specific portion during buffering, and at the same time, pressure shock in the pressurized chamber can be buffered, so that the solder paste can be mixed more effectively with a uniform density. As shown in FIGS. 5 and 6, the sealed squeegee comprises a chamber housing 100, a solder mixing unit 200, a squeegee blade holder 300, a holding mounting unit 400, a pumping coupling unit 500, a chamber sealing cover 600, a pumping pad 700, a side cover 800, and a cover holding member 900.

[0039] The chamber housing 100 is formed so that when the solder paste is supplied onto the mask in front of the squeegee and the chamber housing being parallel to each other, the squeegee follows and prints on the mask according to the mask pattern, and is formed long in a direction intersecting the direction in which the squeegee of the screen printer moves, so as to supply the solder paste to the mask at a uniform density. That is, in order to uniformly mix the solder paste and supply it in a uniform amount as described above, the chamber housing 100 is integrally formed with a solder mixing unit 200, a holding placement unit 400, and a pumping coupling unit 500 as shown in Figs. 5 to 7 described below.

[0040] The solder mixing unit 200 is formed so that solder paste is supplied and stored in a pressure chamber formed penetrating the chamber housing 100 from the left to the right, and is uniformly mixed through a pumping action of a pumping pad (described later) and compressed air, and the solder paste can be discharged on a mask in a fixed amount, preventing the solder paste from being wasted and enabling high quality printing when printing on the mask. The solder mixing unit 200 includes a pressure chamber 210 for uniformly mixing the supplied solder paste, and a nozzle unit 220 provided to maintain a constant pressure within the pressure chamber and enable a fixed amount to be discharged without pressure loss.

[0041] That is, the solder mixing unit 200 is formed such that the pressure chamber 210 has a V-shaped cross section and penetrates the chamber housing in the longitudinal direction so that the solder paste can be uniformly mixed by applying and buffering pressure to the left and right sides of a cross section perpendicular to the longitudinal direction of the chamber housing 100, and a nozzle unit 220 through which the solder paste supplied, received, and uniformly mixed in the pressure chamber 210 is discharged to the outside is formed penetrating the lower surface of the pressure chamber 210.

[0042] 8, when compressed air is supplied through the air injection hole 620 of the chamber sealing cover 600 formed on the left side of the cross section, the pumping through hole 510 is blocked and the pumping pad 700 coupled to the sealing coupling groove 520 expands into the pressure chamber 210 on the left side of the "V" shaped cross section to pressurize and mix the solder paste contained inside the pressure chamber, and the solder paste is mixed uniformly as the pumping pad 700 is deformed and buffered against the inner surface of the chamber sealing cover on the side of the pumping through hole 510 through the pressure chamber 210 on the right side of the "V" shaped cross section due to the pressure shock caused by the expansion pressure of the pumping pad during the pressurization process. When the left side of the pressure chamber 210 is pressurized, the right side buffers the pressure shock inside the pressure chamber 210, and when the right side is pressurized, the left side buffers the pressure shock inside the pressure chamber 210. That is, the pressure chamber 210 is formed to perform pressurization and buffering at the same time, and uniform mixing is performed in the center where the nozzle part is formed.

[0043] To explain this in more detail, in the past, the pressurizing means and the buffering means were separately constructed, and the pressurizing means was coupled to one side of the pressurizing chamber and the buffering means was constructed to provide a buffering means to prevent the problem of pressure shock occurring due to the pressure rise caused by the pressurizing means repeatedly pressurizing the solder paste flowing into the pressurizing chamber, and the buffering means buffers the problem of the pressure rise causing pressure shock occurring due to the pressure rise, and the solder paste is uniformly mixed and then discharged while maintaining the pressure in the pressurizing chamber at a constant pressure. That is, in the past, the pressurizing means and the buffering means were constructed separately, with their respective functions being set in different ways, resulting in a complex structure, and pressurization was performed in one direction and buffering for this was also performed in one direction, which took a considerable amount of time to uniformly mix the solder paste.

[0044] However, in the present invention, by repeatedly applying pressure and buffering in both directions in a cross-like manner, the solder paste can be mixed uniformly and quickly, and the pressure in the pressure chamber can be maintained constant at all times.In addition, there is no need to separately configure the pressure means and buffering means. Instead, the structure is a single structure using a pumping pad (described below) that contracts and expands, making assembly and disassembly easier, shortening the assembly and disassembly time as well as the cleaning time and operation shutdown time.

[0045] Therefore, the pressure chamber 210 having a "V" shaped cross section is configured symmetrically so that both the left and right sides can perform the role of pressurization and buffering, and the solder paste accommodated in the center is mixed to a uniform density through the action of stirring and kneading caused by the pressurization and buffering in both directions, and the uniformly mixed solder paste can be discharged in a fixed amount through the nozzle part 220 formed on the lower surface in the center.

[0046] That is, when a sudden change in volume occurs in the pressurizing chamber on one side of the “V” shape due to a sudden change in pressure caused by the pumping pad which expands and pressurizes with compressed air, a pressure shock occurs. This pressure shock causes repeated increases and decreases in pressure, which causes the discharge amount of the solder paste to repeatedly and irregularly increase and decrease, so the pressure inside the pressurizing chamber must always be maintained constant.

[0047] Therefore, due to the pressure of the pumping pad on one side, which will be described later, the pumping pad on the other side buffers the pressure by an amount corresponding to the pressure, and the same pressure is always maintained within the pressurized chamber. As a result, in the nozzle unit 220, the solder paste can be solidified at the same density and the discharge can be maintained at a constant rate, just as in the case of making rice cakes (stick-shaped rice cakes) by pressurizing and solidifying rice flour, and the rice cakes are discharged at the same thickness and density.

[0048] Meanwhile, as shown in FIG. 6, the squeegee blade holder 300 is provided so that the uniformly mixed solder paste supplied onto the mask is printed and pushed according to the printing pattern by the downward pressure and forward moving force as the squeegee blade moves correspondingly, and is coupled to the front and rear of the underside of the chamber housing 100, and squeegee blades 310 are coupled thereto so that when the solder paste is supplied onto the mask, the solder paste is spread evenly over the mask.

[0049] Here, the squeegee blade 310 is formed long in the front-rear and left-right length directions, and both sides are formed symmetrically. Therefore, the front squeegee blade widely spreads and presses the solder paste discharged onto the mask through the nozzle portion while printing it, and the rear squeegee blade collects the solder paste remaining on the mask. This prevents excessive use of the solder paste and enables optimal use, thereby reducing the economic burden through the proper use of expensive solder paste.

[0050] In addition, only when a fixed amount of solder paste is supplied to the squeegee blade side through the nozzle unit 220 of the solder mixing unit 200 described above, printing can be performed without defects when printing according to the print pattern. This is because if an excessive amount of solder paste is supplied, the remaining solder paste must be removed, which is troublesome, and if the amount of solder paste is small, it is impossible to print according to the print pattern, resulting in printing defects. In other words, it is no exaggeration to say that in the printing process using the squeegee blade, the print quality depends on the fixed amount of solder paste discharged that was previously mixed uniformly.

[0051] Meanwhile, the holding mounting part 400 is formed with a solder injection port for supplying solder paste into the pressurized chamber 210 of the chamber housing 100, and is configured so that a cover holding member 900 is mounted and coupled to cover the pumping coupling part 500 described below and maintain and fix it in an airtight state by the rotating operation of the chamber sealing cover 600 described below. As shown in Figures 6 and 7, the holding mounting part 400 is configured to include a vertical surface 402, a mounting horizontal surface 404, and a solder injection port 406.

[0052] The vertical surface 402 has front and rear vertical surfaces 402 protruding therefrom so that the chamber sealing cover 600, which will be described later, can be rotated on the upper side of the chamber housing 100 to cover the pumping coupling part 500 and maintain airtightness. Here, as shown in FIG. 15, the front and rear vertical surfaces 402 serve to check the state in which the pumping coupling part 500 is covered by the rotating operation of the chamber sealing cover 600 described later. When the vertical surface coincides with the closing surface formed at the end of the chamber sealing cover 600 and the horizontal mounting surface and the holding surface are flush with each other, it can be confirmed that the chamber sealing cover 600 is completely closed. If the vertical surface and the closing surface do not coincide even slightly, the horizontal mounting surface and the holding surface cannot be flush with each other, which causes an error in closing the chamber sealing cover. In effect, the airtight coupling of the pumping coupling part 500 is not maintained, and pressure and cushioning in the pressurized chamber are poor, resulting in incomplete and uniform mixing of the solder paste.

[0053] As shown in FIG. 16 , the mounting horizontal surface 404 is formed such that a cover holding member 900, which will be described later, is placed and coupled to the mounting horizontal surface 404, and the supply through-holes 902 of the cover holding member 900 are aligned with the solder injection holes 406 formed on the mounting horizontal surface 404, so that the solder paste is supplied and received into the pressurized chamber 210 through the supply through-holes 902 and the solder injection holes 406.

[0054] Here, as shown in FIG. 17, the holding mounting part 400 has a larger front-to-rear width of the cover holding member 900 formed in the horizontal plane between the front and rear vertical surfaces 402, and after the chamber sealing cover 600 described below rotates toward the holding mounting part 400, the holding surface formed at the tip of the chamber sealing cover 600 and the horizontal mounting surface 404 become flush with each other, and then the cover holding member 900 is coupled to the horizontal mounting surface 404, and the holding surface of the chamber sealing cover is fixed to the bottom surface coupled to the horizontal mounting surface of the cover holding member 900, thereby controlling the rotation of the chamber sealing cover.

[0055] That is, the solder paste is supplied to the pressurized chamber by the cover holding member 900 through the solder injection port 406 formed in the mounting horizontal surface 404, and the chamber-sealing cover is fixed and coupled to the cover holding member 900 by simultaneously controlling the rotation of the chamber-sealing cover. Here, the front-rear width of the cover holding member 900, which will be described later, for controlling the chamber-sealing cover is formed smaller or larger than the width at which the chamber-sealing cover 600 rotates on the holding mounting part 400 and the mounting horizontal surface 404 and the holding surface 640 are flush with each other, and the rotation of the chamber-sealing cover can be controlled by the cover holding member 900 only when the width is larger than the width of the mounting horizontal surface 404.

[0056] As described above, the solder injection port 406 is formed on the mounting horizontal surface 404 in communication with the pressure chamber 210, and at least one solder injection port 406 is formed so that solder paste supplied from the outside is injected into the pressure chamber 210. That is, as shown in Figs. 6 and 7, one solder injection port 406 is formed in the center, but at least one solder injection port 406 may be formed so that the same solder paste is simultaneously supplied to the pressure chamber 210 formed long in the overall length direction.

[0057] The pumping coupling part 500 is provided with compressed air while maintaining airtightness by the rotation of the chamber sealing cover, and is freely expanded and contracted by the supply and discharge of compressed air, and pumping through holes 510 communicating with the pressurizing chamber 210 are formed symmetrically on the front and rear surfaces in the length direction of the chamber housing 100 to perform the functions of pressurizing, buffering and maintaining pressure in the pressurizing chamber, and sealed coupling grooves 520 are formed on the front and rear surfaces of the chamber housing 100 outside the inner periphery of the pumping through holes 510, and a hinge coupling device 530 is protruded below the sealed coupling grooves 520. That is, the pumping coupling part 500 includes the pumping through holes 510, the sealed coupling grooves 520 and the hinge coupling device 530 as shown in FIG.

[0058] The pumping through-hole 510 is formed to penetrate longitudinally in the center of the pumping coupling part 500 formed on one side where the vertical surface 402 of the holding mount part 400 and the squeegee blade holder 300 are coupled. The pumping through-holes 510 are formed symmetrically in the front and rear of the holding mount part 400, and the pumping through-holes 510 communicating with the pressurized chamber are hermetically sealed by the pumping pad 700 described below.

[0059] The sealed coupling groove 520 is recessed on the outer side of the inner periphery of the pumping through-hole 510 so that the periphery of the pumping pad 700 described later is coupled thereto, and is airtightly coupled thereto so that the central portion of the pumping pad 700 expands and contracts in the pressurized chamber by compressed air. Here, as shown in Figs. 8 and 9, the contact area of ​​the outer periphery of the pumping pad 700 is enlarged through the recessed sealed coupling groove 520, and the outer periphery of the pumping pad is fitted in accordance with the recessed shape of the sealed coupling groove 520 so that the outer periphery of the pumping pad can withstand a force that is pulled toward the pumping through-hole during the contraction and expansion of the pumping pad.

[0060] The hinge couplers 530 are formed symmetrically at the front and rear of the chamber housing 100 at the upper end where the squeegee blade holder is coupled under the sealing coupling groove 520. The hinge couplers 530 are hingedly coupled to a hinge coupling piece 610 of the chamber sealing cover, which will be described later, so that the chamber sealing cover 600 can rotate. As shown in Figs. 5 to 8, the chamber sealing cover 600 presses the pumping pad 700, which will be described later, while rotating on the holding mount 400 as described above. Due to the pressure applied by the chamber sealing cover, the outer periphery of the pumping pad 700 does not come off the sealing coupling groove 520, and the compressed air supplied to the central portion where the sealing cover contracts and expands does not leak out during the process of the pumping pad contracting and expanding, so that the pumping action can be smoothly performed.

[0061] The chamber sealing cover 600 serves to cover the pumping coupling between the hinge coupling 530 on the vertical surface 402 of the holding mount part to maintain airtightness while isolating the pumping coupling between the hinge coupling 530 from the outside in order to maintain airtightness during the supply and discharge of compressed air for contraction and expansion of the pumping pad 700 coupled to the pumping through hole 510 of the pumping coupling part 500 as described above, and is configured to rotate from the hinge coupling 530 side to the holding mount part side in order to apply pressure to maintain the coupling of the pumping pad. 14 to 17, the chamber sealing cover 600 is formed as a rectangular plate having a length corresponding to the left and right length of the chamber housing 100 in order to cover the pumping coupling part 500 so as not to expose it to the outside, and a hinge coupling piece 610 hinged to the hinge coupling device 530 is formed on the lower side of the rectangular plate, and is provided to cover the pumping coupling part 500 by rotating, and a number of air injection holes 620 are formed symmetrically in the front and rear on the outer surface so that compressed air is supplied and discharged to the pumping through hole 510 side of the pumping coupling part 500. That is, the chamber sealing cover 600 includes the hinge coupling piece 610 and the air injection hole 620 as shown in FIGS. 5 and 6.

[0062] The hinge coupling piece 610 is hinged to the hinge coupling device 530 of the pumping coupling part 500 as described above, so that the chamber sealing cover 600 formed in the shape of a rectangular plate can be rotated toward the holding mounting part 400. By configuring the chamber sealing cover 600, it becomes easy to replace the pumping pad 700 (described later) which is coupled to the sealing coupling groove 520 formed on the outer periphery of the pumping through hole 510 of the pumping coupling part 500. Therefore, when the pumping pad is damaged or broken or reaches the end of its service life, it can be easily replaced by opening the chamber sealing cover, thereby minimizing the downtime.

[0063] The air injection hole 620 is configured to supply or discharge compressed air to the expanding and contracting parts of the pumping pad fitted in the pressurized chamber through the pumping through hole so that the inner surface of the chamber sealing cover 600 in contact with the pumping coupling part 500 pressurizes the outer periphery of the pumping pad 700 to maintain airtightness, and the pumping pad 700 is coupled to the air injection hole 620 and expands and contracts within the pressurized chamber 210 with the pumping through hole 510 closed.

[0064] That is, as shown in FIGS. 8 to 13, when compressed air is supplied through the air injection hole 620, the portion of the pumping pad fitted inside the pressurizing chamber expands, causing a volume change inside the pressurizing chamber 210. Due to this volume change, the air inside the pressurizing chamber 210 pressurizes the solder paste contained therein by the amount of the volume change. As the solder paste moves to the opposite side of the pressurizing chamber having a "V" shaped cross section, the air inside the opposite pressurizing chamber pushes out the pumping pad 700 on the opposite side. When compressed air is supplied to the pumping pad 700 on the opposite side again, the pressure moves due to the volume change inside the pressurizing chamber in the reverse order to the above, thereby uniformly mixing and pressurizing the solder paste.

[0065] Therefore, the pumping pad 700 expands and contracts due to the compressed air supplied and discharged through the air injection hole 620, and the solder paste in the pressure chamber 210 moves in the direction in which the pressure change occurs according to the changing volume, and is stirred and mixed, so that the solder paste is mixed uniformly. In addition, the pressure in the pressure chamber 210 is always maintained at the same pressure due to the pressure caused by the constant volume change, and the pumping pad repeats pressurization and contraction, so that the solder paste is mixed uniformly and a fixed amount can be easily discharged. That is, by controlling the supply and discharge of compressed air so that excessive pressure change does not occur, the pumping pad also expands and contracts at the same rate, and the pressure in the pressure chamber is also maintained at the same rate with the same volume change, so that the discharge of the solder paste through the nozzle is always maintained constant.

[0066] Meanwhile, as shown in FIG. 2 and FIG. 14, the chamber sealing cover 600 has a closing surface 630 at the end opposite to the end where the hinge connection piece 610 is formed, the closing surface 630 being in contact with the vertical surface 402 of the holding mounting part 400, and a holding surface 640 being perpendicular to the closing surface 630 and being flush with the mounting horizontal surface 404. The holding surface 640 is formed so that, after the closing surface 630 is in contact with the vertical surface 402 and is flush with the mounting horizontal surface 404, the lower surface of the cover holding member 900 presses the holding surface 640 as the cover holding member 900 is coupled to the mounting horizontal surface 404, thereby controlling the rotation operation for opening the chamber sealing cover 600.

[0067] As described above, the pumping pad 700 is configured to change the volume of the pressurized chamber 210 and perform a pressure change applied to the solder paste and a buffering action due to the pressure change. The pumping pad 700 is configured to minimize and limit the occurrence of pressure shock due to pressure changes in the pressurized chamber by repeatedly blowing a balloon to the same size, expanding it, and then returning it to its original state, thereby enabling uniform mixing and constant discharge of the solder paste. As shown in FIGS. 8 to 13, the pumping pad 700 is airtightly coupled to the sealed coupling groove 520 while blocking the pumping through-hole 510 formed in the pumping coupling part 500, and is configured to maintain airtight coupling with the pumping coupling part 500 as the chamber sealing cover 600 rotates toward the holding placement part 400. The pumping pad 700 is configured to perform a pumping action such that the solder paste contained in the pressurized chamber is uniformly mixed by repeatedly expanding and contracting inwardly of the pressurized chamber 210 connected to the pumping through-hole 510 by compressed air supplied and discharged through a plurality of air injection holes.

[0068] The pumping pad 700 performs pumping by repeatedly expanding and contracting within the pressurized chamber 210 and the pumping through-hole 510 due to the pressure of compressed air supplied through a number of air injection holes 620 formed in the chamber sealing cover 600 as described above, and is formed to a length corresponding to a length capable of sealing the pumping through-hole 510. As shown in FIG. 9, the pumping pad 700 includes a sealing part 710 and a pressurized buffer part 720.

[0069] As described above, the sealing part 710 is formed to have a shape corresponding to the sealed coupling groove 520 so as to be fitted therein, and is hermetically coupled to the sealed coupling groove 520 formed on the inner peripheral edge of the pumping through-hole 510, thereby preventing the sealing part 710 from coming off the sealed coupling groove due to elastic deformation and elastic restoring force caused by the contraction and expansion of the pressurized buffer part 720 described later, and achieving a more reliable hermetic coupling by increasing the contact area for hermetic coupling.

[0070] As described above, the pressurization buffer part 720 is configured to cause a volume change in the pressurization chamber 210 by contracting and expanding while being inserted into the pressurization chamber 210, thereby generating a pressure change and a pressurizing force, thereby uniformly mixing the solder paste. The pressurization buffer part 720 is formed to extend inside the sealing part 710 and recessed into the pressurization chamber 210 from the pumping through hole 510, and expands toward the pressurization chamber 210 by compressed air supplied through a plurality of air injection holes 620 formed in the chamber sealing cover 600, and contracts and buffers due to the pressure shock inside the pressurization chamber 210, thereby uniformly mixing the solder paste inside the pressurization chamber.

[0071] Here, it is preferable that the pressurized buffer part 720 is formed of any one of rubber or synthetic rubber, elastic synthetic resin, and silicone, which have elasticity that allows easy elastic deformation and quick elastic recovery depending on the supply amount of compressed air supplied through the air injection hole. In addition to the above material configurations, any material that allows easy elastic recovery and elastic deformation by supplying and discharging compressed air belongs to the pumping pad of the present invention.

[0072] 5 and 6, the side cover 800 is coupled to the chamber housing 100 so that the pressurized chamber 210 opened to the left and right sides is sealed, and an air vent 810 is formed through the side cover 800 so that the air inside the pressurized chamber 210 of the chamber housing 100 is discharged and the inflow of external air is blocked. That is, the side cover 800 is formed so that the air inside the pressurized chamber 210 is discharged to the outside and the external air is not allowed to flow inside, and the air vent of the side cover 800 blocks the inflow of external air and discharges the internal air to the outside as the pressure of the internal air inside the pressurized chamber is applied to the air vent side due to the volume change of the pressurized chamber with the expansion of the pumping pad.

[0073] As shown in Figures 5 and 6, the cover holding member 900 supplies solder paste to the solder injection port 406 and controls the chamber sealing cover 600 to prevent it from rotating and spreading out again after being folded. It is formed long in the left and right length directions, and as shown in Figure 17, it is connected to the mounting horizontal surface 404 so as to restrict the rotation of the chamber sealing cover 600 that has been rotated toward the holding mounting part 400, and is provided with a supply through hole 902 that supplies solder paste while communicating with the solder injection port 406 formed in the mounting horizontal surface 404.

[0074] 16 and 17, only when the cover holding member 900 is released, the rotation of the chamber sealing cover 600 is released from the pumping coupling portion 500, and the chamber sealing cover 600 is released while rotating, thereby making it possible to replace the pumping pad 700 or clean the inside of the pressurized chamber. That is, the cover holding member 900 serves as a key that controls the rotation of the chamber sealing cover, and ultimately serves as a key that enables replacement of the pumping pad 700 or cleaning to remove solder paste remaining in the chamber housing 100 and the pressurized chamber 210.

[0075] To explain how to assemble the sealed squeegee of the present invention capable of supplying solder paste at a uniform density according to the above-mentioned configuration, as shown in FIG. 14, first, a chamber housing 100 is prepared in which a pressurized chamber 210 is formed long in the left and right directions and penetrating toward the center of the chamber housing 100, and a solder mixing section 200 made up of a nozzle section from which solder paste can be discharged is integrally formed inside the pressurized chamber 210. Squeegee blades 310 are then attached to the front and rear lower parts of the chamber housing 100 by squeegee blade holders 300, centered on nozzle section 220.

[0076] Thereafter, the hinge connection piece 610 of the chamber sealing cover 600 is hinged to correspond to the hinge connection device 530 constituting the pumping connection part 500 of the chamber housing 100, so that the chamber sealing cover 600 is connected to the holding mounting part 400 formed on the upper side of the chamber housing 100 so as to be pivotable.

[0077] Next, as shown in Figures 14 and 15, the side cover 800 is coupled to the left and right ends of the chamber housing 100 to hermetically couple the left and right sides of the pressurized chamber 210, and then the sealing portion 710 of the pumping pad 700 is hermetically fitted into the sealed coupling groove 520 formed around the pumping through hole 510 of the pumping coupling portion 500, and as a result of the coupling of the pumping pad 700, the pressurized buffer portion 720 of the pumping pad 700 is coupled to the inside of the pressurized chamber 210 through the pumping through hole 510 so as to contract and expand.

[0078] Next, as shown in Figures 15 and 16, the chamber sealing cover 600 rotates toward the holding mounting portion 400, and as the chamber sealing cover 600 rotates toward the holding mounting portion 400, the closing surface 630 of the right-angled chamfered portion at the tip of the chamber sealing cover that corresponds to the vertical surface 402 comes into contact with the vertical surface 402 of the holding mounting portion 400, and at the same time, the holding surface 640 formed at a right angle to the closing surface 630 of the chamber sealing cover is coupled to be flush with the mounting horizontal surface 404 of the holding mounting portion 400.

[0079] Next, as shown in FIG. 17, the cover holding member 900 is placed and coupled on the horizontal mounting surface 404 of the holding mounting part, and the solder injection port 406 formed on the horizontal mounting surface 404 and the supply through hole 902 of the cover holding member 900 are coupled to communicate with each other, and the bottom sides of the front and rear ends of the cover holding member 900 are pressed against the holding surface 640 formed on the end of the chamber sealing cover 600 while being placed and coupled, so that the chamber sealing cover 600 is maintained in a state of being rotated toward the holding mounting part 400, and the rotation is controlled, thereby acting as a lock.

[0080] Thereafter, compressed air is supplied through the air injection hole 620 of the chamber sealing cover 600, and the compressed air causes a volume change in the pressurized buffer portion 720 of the pumping pad 700 on the left or right side of the “V” shaped cross section of the pressurized chamber 210, whichever side the pressurized buffer portion 720 expands first due to the compressed air, and the internal air within the pressurized chamber 210 is discharged through the air vent 810 of the side cover 800, pressurizing the solder paste contained therein.

[0081] Next, the pressurized solder paste is stirred and mixed at the center side where the nozzle part 220 is formed at the bottom, and the solder paste moves to the opposite side of the “V” shape due to the pressure caused by the pressurization, generating a pressure shock. At this time, if the pressure shock cannot be buffered, a problem may occur in which the pressure change of the solder paste being stirred and mixed on the nozzle part 220 side is not constant and the pressure increases or decreases. However, the pressure buffer part 720 of the pumping pad 700 on the opposite side receives the pressure shock due to the volume change, and then compensates for the volume change by contracting and elastically deforming towards the chamber sealing cover 600 side.

[0082] Therefore, as shown in FIGS. 8 and 9, while maintaining a constant pressure without a decrease or increase in pressure change due to pressure shock, pressurization and buffering are performed by the pressurization buffer part 720 of the pumping pad 700, buffering the pressure shock, and when compressed air is supplied to the opposite pressurization buffer part 720 that has contracted and elastically deformed to expand it, it acts in the opposite manner to the above-mentioned part, and pressurization and buffering are performed by the pumping pads 700 on the left and right sides crossing each other based on the pressurization chamber 210 having a ``V'' shaped cross section, so that the solder paste can be uniformly mixed in the pressurization chamber 210, and a constant solder paste can be discharged through the nozzle part while the pressure state due to the volume change in the pressurization chamber 210 is maintained as it is.

[0083] Through the pumping action of the pumping pad 700 as described above, the solder paste in the pressurized chamber 210 can be uniformly mixed and a constant pressure can be maintained easily, and the solder paste can be uniformly supplied to improve the mask printing quality. When the pumping pad responsible for direct pumping in the sealed squeegee capable of supplying solder paste at a uniform density according to the present invention as assembled as described above is damaged or reaches the end of its useful life and needs to be replaced, the pumping pad 700 can be quickly and easily removed by simply releasing the connection between the chamber housing 100 and the cover holding member 900 and then rotating the chamber sealing cover 600 to open, and can be easily replaced without any special skills, thereby minimizing the downtime and reducing the production time and overall tact time.

[0084] Furthermore, when replacing with a different type of solder paste, the chamber housing 100 can be easily and quickly disassembled by releasing the connection between the cover holding member 900 and the chamber housing 100 in the reverse order of the assembly process described above, allowing for quick cleaning and preventing defects caused by mixing of different types of solder paste due to remaining solder paste.

[0085] Meanwhile, the pumping pad 700 has a cross section corresponding to half of a square shape and is a part that contracts and expands inside the pressure chamber, which will be described in more detail with reference to other embodiments.

[0086] <Example 1> The cross section of the pumping pad 700 is configured in a "W" shape. In order to achieve the above shape, in the basic configuration of the pumping pad 700 of the present invention, which includes a sealing part and a pressure buffer part 720, the pressure buffer part 720 is expanded by the expansion of compressed air supplied through the solder injection port 406 into the pressure chamber 210 to pressurize the solder paste, and the pressure shock in the pressure chamber due to the pressurization is buffered by quickly contracting, so that a buffer expansion and contraction part 722 is formed in the center of the pressure buffer part in the length direction, recessed from the pressure chamber to the pumping through hole side, and the "∩"-shaped buffer expansion and contraction part 722 is formed recessed upward from the center of the "U"-shaped cross section of the pressure buffer part 720, which is the basic configuration shown in Figures 8 and 9, so that the overall cross section has a "W" shape as shown in Figures 10 and 11.

[0087] With the above-mentioned "W" shaped cross section formed, the pressurized buffer unit 720 is configured with the buffer expansion / contraction unit 722 arranged on the left and right sides at the center. When compressed air is supplied through the solder injection port 406, the pressurized buffer units 720 arranged and formed on the left and right sides begin to expand, and as they continue to expand, the buffer expansion / contraction unit 722 formed in the center expands while elastically deforming inside the pressurized chamber 210, causing a volume change in the pressurized chamber 210. The air inside the pressurized chamber due to the volume change is discharged to the outside through the air vent 810, and the pressure due to the volume change pressurizes the solder paste contained in the pressurized chamber.

[0088] Then, the buffer expansion / contraction part 722 of the pumping pad formed symmetrically on the opposite side is recessed toward the pumping through-hole 510, so that the pressure change due to the volume change and the resulting pressure shock are primarily buffered through the recessed space of the buffer expansion / contraction part 722. When a pressure shock occurs due to a pressure greater than this, the buffer expansion / contraction part 722 continues to expand toward the pumping through-hole 510, and the pressurized buffer parts 720 formed on the left and right sides deform toward the pumping through-hole 510 through elastic deformation, so that the pressure is buffered more quickly.

[0089] Therefore, the buffer expansion / contraction unit 722 is configured to further change the volume within the pressurized chamber, thereby further increasing the pressure applied to the solder paste contained in the pressurized chamber, and to more quickly buffer the pressure shock within the pressurized chamber through the space recessed into the pumping through-hole side. The pressurized buffer unit 720 formed in the basic configuration alone is sufficient to uniformly mix the solder paste and maintain a constant pressure within the pressurized chamber, but it can be applied when it is necessary to mix the solder paste more quickly and uniformly by changing the pressure and buffering depending on different types of solder paste, and of course it can also be applied to general cases where the basic pressurized buffer unit 720 is formed alone.

[0090] <Example 2> The cross section of the pumping pad 700 is configured in a wrinkled shape. In order to achieve the above shape, the buffer expansion and contraction part 722 is formed in the basic configuration of the pumping pad 700 of the present invention, which is configured to include the sealing part and the pressurizing buffer part 720, and is recessed from the center of the buffer expansion and contraction part 722 toward the pressurizing chamber 210 at a length corresponding to the length direction of the pumping through hole 510, and a sub-pressurizing buffer part 724 is additionally formed in the buffer expansion and contraction part so that the buffer expansion and contraction part can easily expand toward the pressurizing chamber side by compressed air. As a result, the "∩"-shaped buffer expansion and contraction part 722 is formed recessed upward from the center of the "U"-shaped cross section of the pressurizing buffer part 720, which is the basic configuration shown in Figures 8 and 9, and the "U"-shaped sub-pressurizing buffer part 724 is formed in the center of the "∩"-shaped buffer expansion and contraction part 722 when the cross section becomes "W"-shaped as shown in Figures 10 and 11, and the entire cross section is formed in a wrinkled shape as shown in Figures 12 and 13. As a result of the formation of the wrinkled cross section as described above, the pressurizing buffer 720 and the buffer expansion / contraction unit 722 are arranged on the left and right sides of the sub pressurizing buffer 724, and when compressed air is supplied through the solder injection port 406, the sub pressurizing buffer 724 recessed in the center toward the pressurizing chamber starts to expand first, and the pressurizing buffers 720 arranged on both the left and right ends also expand into the inside of the pressurizing chamber. Then, as the sub pressurizing buffer 724 and the pressurizing buffer 720 continue to expand, the buffer expansion / contraction unit 722 formed between the sub pressurizing buffer 724 and the pressurizing buffer 720 expands while being elastically deformed into the pressurizing chamber 210, causing a volume change in the pressurizing chamber 210, and the air inside the pressurizing chamber is discharged to the outside through the air vent 810 due to the volume change, and the pressure due to the volume change pressurizes the solder paste contained in the pressurizing chamber.Then, the buffer expansion / contraction part 722 of the pumping pad formed symmetrically on the opposite side is recessed toward the pumping through-hole 510, so that the pressure change due to the volume change and the resulting pressure shock are primarily buffered through the recessed space of the buffer expansion / contraction part 722, and the pressure shock generated by a pressure greater than this is secondarily buffered by the sub pressurizing buffer part 724 elastically deforming toward the pumping through-hole 510 and then expanding. The pressurizing buffer parts 720 formed at both the left and right ends also elastically deform toward the pumping through-hole 510 and then expand, so that pressure buffering can be performed most quickly and precisely through tertiary buffering.

[0091] Therefore, the sub-pressure buffer 724 is configured such that the resistance to the compressed air is minimized by forming the inner portion of the sealed portion of the pumping pad in a wrinkled shape, and at the same time, the expansion is performed quickly, thereby quickly changing the volume change in the pressure chamber, quickly increasing the pressure applied to the solder paste contained in the pressure chamber, and also quickly and accurately buffering pressure shocks.

[0092] As a result, without the need to separately configure a pressurizing means or buffering means having a complicated configuration, the solder paste is mixed at a uniform density through the pumping action of the pumping pad 700, which can simultaneously pressurize and buffer, and the pressure is maintained constant while minimizing pressure changes in the pressurizing chamber, making it easier to discharge a fixed amount of solder paste through the mask. Also, as mentioned above, it becomes easy to replace only the pumping pad 700, and disassembly and assembly for easy cleaning becomes simple and quick, so cleanability for replacing different types of solder paste is also improved. [Explanation of symbols]

[0093] 100 chamber housing 200 Solder Mixing Section 400 Holding Placement 500 Pumping Joint

Claims

1. A chamber housing (100) that is elongated in a direction intersecting the direction in which the squeegee of the screen printer moves, for supplying solder paste to the mask at a uniform density; a solder mixing section (200) having a V-shaped cross section on the left and right sides of a cross section perpendicular to the longitudinal direction of the chamber housing (100) so that the solder paste is uniformly mixed through pressure application and pressure buffering, a pressure chamber (210) penetrating the length of the chamber housing in the longitudinal direction, and a nozzle section (220) for discharging the solder paste supplied, received and uniformly mixed in the pressure chamber (210) to the outside, the nozzle section (220) penetrating the lower surface of the pressure chamber (210); a squeegee blade holder (300) coupled to the front and rear of the underside of the chamber housing (100) and coupled to a squeegee blade (310) arranged to spread the solder paste evenly on the mask when the solder paste is applied on the mask; a holding mounting part (400) having front and rear vertical surfaces (402) protruding from the upper side of the chamber housing (100), a mounting horizontal surface (404) formed long in the left and right length direction and having at least one solder injection port (406) formed on the upper surface in communication with the pressure chamber (210) and for injecting solder paste supplied from the outside into the pressure chamber (210); a pumping coupling part (500) in which pumping through holes (510) communicating with the pressurizing chamber (210) are formed symmetrically on the front and rear surfaces in the longitudinal direction of the chamber housing (100), sealing coupling grooves (520) are formed on the front and rear surfaces of the chamber housing (100) outside the inner periphery of the pumping through holes (510), and hinge coupling devices (530) are protruded below the sealing coupling grooves (520); a chamber sealing cover (600) formed symmetrically in the front and rear, in the form of a rectangular plate having a length corresponding to the length in the left and right direction of the chamber housing (100) to cover the pumping coupling part (500) so that the pumping coupling part (500) is not exposed to the outside, and a hinge coupling piece (610) is formed on the lower side of the rectangular plate to be hingedly coupled to the hinge coupling device (530), and the chamber sealing cover (600) is provided to cover the pumping coupling part (500) by a rotating operation, and has a number of air injection holes (620) formed on the outer surface so that compressed air is supplied to and discharged from the pumping through hole (510) side of the pumping coupling part (500); a pumping pad (700) that is airtightly connected to the sealed connection groove (520) while blocking the pumping through hole (510) formed in the pumping connection part (500), and that is formed so that the chamber sealing cover (600) rotates toward the holding placement part (400) to maintain airtight connection with the pumping connection part (500), and that performs a pumping action so that the solder paste contained in the pressure chamber is uniformly mixed by repeatedly expanding and contracting inwardly the pressure chamber (210) that is connected to the pumping through hole (510) by compressed air supplied and discharged through a number of air injection holes; a side cover (800) to which the pressurized chamber (210) open to the left and right sides of the chamber housing (100) is connected so as to be sealed, and through which an air vent (810) is formed so as to exhaust the internal air of the pressurized chamber (210) of the chamber housing (100) and block the inflow of external air; a cover holding member (900) formed long in the left-right length direction, coupled to the mounting horizontal surface (404) so ​​as to restrict the rotation of the chamber sealing cover (600) rotated toward the holding mounting part (400), and provided with a supply through hole (902) communicating with a solder injection port (406) formed on the mounting horizontal surface (404) to supply solder paste at a uniform density.

2. 2. The sealed squeegee according to claim 1, wherein when compressed air is supplied through the air injection hole (620) of the chamber sealing cover (600) formed on the left side of the cross section, the pumping pad (700) coupled to the sealing coupling groove (520) expands into the pressure chamber (210) on the left side of the “V” shaped cross section while blocking the pumping through hole (510), thereby pressurizing and mixing the solder paste contained inside the pressure chamber. During the pressurization process, the pressure shock caused by the expansion pressure of the pumping pad is absorbed by the pumping pad (700) passing through the pressure chamber (210) on the right side of the “V” shaped cross section and deforming into the inner surface of the chamber sealing cover on the side of the pumping through hole (510), thereby uniformly mixing the solder paste. When the left side of the pressure chamber (210) is pressurized, the right side absorbs the pressure shock inside the pressure chamber (210), and when the right side is pressurized, the left side absorbs the pressure shock inside the pressure chamber (210).

3. 2. The closed-type squeegee according to claim 1, wherein the chamber sealing cover (600) has a closing surface (630) at an end opposite to the end where the hinge connection piece (610) is formed, the closing surface (630) being in contact with the vertical surface (402) of the holding mounting part (400) and a holding surface (640) being formed perpendicular to the closing surface (630) and being flush with the mounting horizontal surface (404), and the holding surface (640) is formed such that, after the closing surface (630) is in contact with the vertical surface (402) and is flush with the mounting horizontal surface (404), the lower surface of the cover holding member (900) presses against the holding surface (640) as the cover holding member (900) is coupled to the mounting horizontal surface (404), thereby controlling a rotational movement for opening the chamber sealing cover (600).

4. 4. The sealed squeegee capable of supplying solder paste at a uniform density as described in claim 3, wherein the front-to-rear width of the cover holding member (900) is formed smaller or larger than the width in which the mounting horizontal surface (404) and the holding surface (640) are flush with each other as the chamber sealing cover (600) rotates to the holding mounting portion (400), and is formed larger than the width of the mounting horizontal surface (404).

5. The pumping pad (700) pumps by repeatedly expanding and contracting in the pressurized chamber (210) and the pumping through-hole (510) due to the pressure of compressed air supplied through a number of air injection holes (620) formed in the chamber sealing cover (600), and a sealing part (710) formed with a length corresponding to a length capable of sealing the pumping through-hole (510) and airtightly coupled to a sealing coupling groove (520) formed on the inner periphery of the pumping through-hole (510); and a pressure buffer part (720) that is formed to extend inside the sealing part (710) and recess into the inside of the pressure chamber (210) from the pumping through hole (510), and expands toward the pressure chamber (210) by compressed air supplied through a plurality of air injection holes (620) formed in the chamber sealing cover (600), or contracts and buffers due to pressure shock within the pressure chamber (210), thereby uniformly mixing the solder paste within the pressure chamber.

6. 6. The closed squeegee capable of supplying solder paste at a uniform density as set forth in claim 5, wherein a buffer expansion and contraction part (722) is further formed in the center of the pressurizing buffer part in a longitudinal direction and recessed from the pressurizing chamber to a pumping through hole side so as to further expand into the pressurizing chamber (210) as the pressurizing buffer part (720) expands, thereby pressurizing the solder paste, and to buffer a pressure shock in the pressurizing chamber due to pressurization through rapid contraction, and an overall cross section of the pressurizing buffer part and the buffer expansion and contraction part is formed in a “W” shape.

7. 7. The closed squeegee capable of supplying solder paste at a uniform density as set forth in claim 6, wherein the buffer expansion and contraction part (722) is recessed toward the pressurizing chamber (210) at a center thereof with a length corresponding to a length direction of the pumping through hole (510), a sub-pressurizing buffer part (724) is further formed in the buffer expansion and contraction part to facilitate expansion toward the pressurizing chamber by compressed air, and the entire cross section is formed into a wrinkled cross section.

8. 2. The sealed squeegee according to claim 1, wherein the pumping pad (700) is made of any one of rubber or synthetic rubber, elastic synthetic resin, and silicone that has elasticity that allows it to contract and expand while returning to its original state.

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