Technical Field

The present application relates to a solder paste addition device, in particular to a solder paste nozzle and a worktable for an automatic solder paste addition device capable of automatically removing residual solder paste.

Background Art

In the surface mount technology of printed circuit boards, solder paste printers (also called stencil printers) are used to print solder paste onto electronic products (such as circuit boards). A solder paste printer generally comprises a screen plate (or stencil), a solder paste addition device, a scraping blade or scraper, and other mechanisms. During printing, the circuit board is automatically fed into the solder paste printer. The circuit board has a pattern of solder pads or some other conductive surfaces on which solder paste can be deposited, and the circuit board has one or more small holes or marks, called datum points, which are used as reference points to align the circuit board with the screen plate in the solder paste printer before printing solder paste on the circuit board. After the circuit board has been aligned with the screen plate in the printer, solder paste is dispensed by moving a scraping blade or scraper across the screen plate to force the solder paste to pass through the holes in the screen plate and fall onto the circuit board. After the printing operation, the circuit board is then delivered to another workstation in the processing line of printed circuit boards.

The automatic solder paste addition device on the solder paste printing machine is used for automatically adding tanked or canned solder paste to the screen plate of the solder paste printer so as to supplement the solder paste consumed in the printing process. The solder paste tank and the solder paste nozzle inserted into the solder paste tank from the opening of the solder paste tank usually form a solder paste tank assembly, and the solder paste is dispensed (or extruded) from the solder paste tank through relative displacement of the solder paste tank and the solder paste nozzle. When the automatic solder paste addition device is used, the solder paste tank assembly is first mounted on the automatic solder paste addition device, such that the opening of the solder paste tank faces downward. Then the solder paste tank assembly is moved to a certain position above the screen plate (this action is simply referred to as "positioning"), and then the solder paste is dispensed to the screen plate from the solder paste tank nozzle by means of actions such as extrusion or extraction (this action is simply referred to as "solder addition"). After the solder paste is dispensed from the solder paste tank nozzle to the screen plate by means of actions such as extrusion or extraction, there will usually be residual solder paste near the outlet of the solder paste nozzle. In the process of removing residual solder paste, the residual solder paste is not easy to clean because of its high adhesiveness, and the residual solder paste tends to be introduced to parts where solder paste is unwanted. Summary of the Invention

The purpose of the present application is to provide a solder paste addition device capable of automatically removing residual solder paste, which can effectively and automatically remove the residual solder paste at an outlet of a solder paste nozzle of the automatic solder paste addition device at a relatively low cost.

According to a first aspect of the present application, the present application provides a solder paste nozzle comprising: a main body having an end; and a through-hole extending through the main body, with an outlet of the through-hole being disposed at the end, wherein the end has at least one inclined face extending through the through-hole.

In the solder paste nozzle described above, the at least one inclined face comprises two inclined faces which are symmetrically disposed with respect to the through-hole.

In the solder paste nozzle described above, the main body is cylindrical and has a head with an increased diameter, an inlet of the through-hole is disposed at the head, and the diameter of the end of the main body is smaller than the diameter of the rest of the main body.

In the solder paste nozzle described above, the at least one inclined face of the solder paste nozzle is used for guiding gas flow to remove residual solder paste.

According to a second aspect of the present application, the present application provides a worktable of a solder paste addition device, the worktable comprising: an opening, the opening extending through the worktable; at least one air duct, each of the at least one air ducts comprising an air duct inlet and an air duct outlet, the air duct inlet being used to communicate with a gas source so as to deliver gas flow from the gas source to the air duct outlet, and the at least one air duct being configured to provide gas flow in a downward inclined direction. In the worktable described above, the opening has an inner side wall, and the air duct outlet is disposed in the inner side wall of the opening.

In the worktable described above, a lower part of the inner side wall of the opening is inclined away from the opening, and the air duct outlet is disposed in the lower part of the inner side wall.

In the worktable described above, the air duct comprises a first air duct part and a second air duct part, the first air duct part being connected to the gas source, the second air duct part being connected to the air duct outlet, and the second air duct part being inclined such that the gas flow blown out of the air duct outlet is inclined downward.

In the worktable described above, the at least one air duct comprises two air ducts, and the two air ducts are symmetrically disposed with respect to the opening.

In the worktable described above, the at least one air duct comprises two air ducts.

In the worktable described above, the two air ducts are symmetrically disposed with respect to the opening, and the air duct outlets of the two air ducts are symmetrically disposed with respect to the opening.

In the worktable described above, the air duct outlet is flat such that the gas flow flowing out of the air duct outlet is sharper.

In the worktable described above, the air duct is configured to provide gas flow to the inclined face of the end of the solder paste nozzle accommodated in the worktable.

According to a third aspect of the present application, there is also provided a solder paste addition device comprising: a solder paste nozzle, comprising: a main body having an end; a through-hole extending through the main body, with an outlet of the through-hole being disposed at the end, wherein the end has at least one inclined face extending through the through-hole; and at least one air duct disposed to provide gas flow to the at least one inclined face of the end, thereby cutting residual solder paste at the end.

The solder paste addition device as described above further comprises a worktable, the worktable comprising an opening extending through the worktable, the end of the solder paste nozzle being inserted into the opening of the worktable, and the at least one air duct being disposed in the worktable and being configured to be capable of delivering gas flow toward the at least one inclined face of the end of the solder paste nozzle.

In the solder paste addition device described above, the inclination angle of the gas flow blown out of the at least one air duct is smaller than the inclination angle of the at least one inclined face of the end of the solder paste nozzle. In the solder paste addition device described above, the width of the at least one air duct outlet is not less than the width of the outlet of the through-hole of the solder paste nozzle.

The device and the nozzle provided by the present application cooperate with each other, so that residual solder paste at the outlet of the nozzle can be removed more thoroughly. Moreover, since the end of the solder paste nozzle has a downward inclined face and the gas flow is also configured to flow obliquely downward, the residual solder paste cut off by the gas flow can be guided to fall below the nozzle at a position where the solder paste needs to be dispensed without being dispersed to other unwanted positions.

Brief Description of the Drawings

These and other features, aspects and advantages of the present application will become better understood when the following detailed description is read in conjunction with the accompanying drawings, in which the same reference numerals refer to the same parts throughout the drawings, and in which:

Fig. 1 is a perspective view of a solder paste addition device of the present application;

Fig. 2A is a perspective view of a solder paste nozzle of the present application;

Fig. 2B is a perspective view of another angle of the solder paste nozzle in Fig. 2A; Fig. 2C is a cross-sectional view of the solder paste nozzle in Fig. 2A;

Fig. 3A is a perspective view of a worktable of the present application;

Fig. 3B is a perspective view at another angle of the worktable in Fig. 3A;

Fig. 3C is a partial cross-sectional view of the worktable in Fig. 3A, with a solder paste nozzle being mounted on the worktable;

Fig. 4A is a cross-sectional view of the solder paste nozzle shown in Fig. 2A assembled in a solder paste tank and assembled on the worktable shown in Fig. 3A; and

Fig. 4B is an enlarged partial view of Fig. 4A.

Detailed Description of Embodiments

Various particular embodiments of the present application will be described below with reference to the accompanying drawings, which form a part of the specification. It should be understood that although terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "inner" and "outer", are used in the present application to describe various exemplary structural parts and elements of the present application, these terms are used herein only for convenience of illustration and are determined based on exemplary orientations shown in the drawings. Since the embodiments disclosed in the present application can be disposed in different directions, these terms indicating directions are only for illustration and should not be considered as limitations. Wherever possible, the same or similar reference numerals used in the present application refer to the same parts.

Fig. 1 shows a perspective and exploded view of a solder paste addition device 100 of the present application. As shown in Fig. 1, the solder paste addition device 100 comprises a driving device 160, a support plate assembly 130, a push rod 110, a pressing plate 109 and a worktable 300. The support plate assembly 130 is used to support the entire solder paste addition device 100 on a solder paste printer. The pressing plate 109 is disposed at a lower part of the push rod 110, and the push rod 110 can be driven by the driving device 160 to move up and down, thereby driving the pressing plate 109 to move up and down accordingly. The driving device 160 is fixed to the support plate assembly 130, and the worktable 300 is also fixed to the support plate assembly 130. The worktable 300 is used to carry a solder paste tank 107 and a solder paste nozzle 200 accommodated in the solder paste tank 107, wherein a lower end of the solder paste nozzle 200 is supported by the worktable 600 and an upper end of the solder paste nozzle 200 is inserted into the inverted solder paste tank 107. When the solder paste addition operation is performed, the bottom of the inverted solder paste tank 107 is pressed by the downward movement of the pressing plate 109, causing the solder paste tank 107 to move downward relative to the solder paste nozzle 200, so that the solder paste contained in the solder paste tank 107 flows out from the nozzle opening (not shown in Fig. 1) at the lower end of the solder paste nozzle 200. Since the solder paste has certain adhesiveness, there is usually solder paste left at the nozzle opening of the solder paste nozzle 200 after the solder paste addition operation is completed. The solder paste addition device of the present application can automatically remove the residual solder paste by setting the solder paste nozzle and the worktable.

Figs. 2A and 2B show perspective views of the solder paste nozzle 200 of the present application from two angles of view, and Fig. 2C is a cross-sectional view of the solder paste nozzle in Fig. 2A. As shown in Figs. 2A-2C, the solder paste nozzle 200 has a cylindrical main body 210 and a through-hole 218 extending through the main body 210 in an axial direction of the main body 210. The main body 210 has a head 230 with an increased diameter and an end 202 opposite the head 230. The diameter of the head 230 matches the inner diameter of the solder paste tank 107 (see Fig. 4B), so that the solder paste contained in the solder paste tank 107 can flow out through the through-hole 218 of the solder paste nozzle when the solder paste tank 107 moves downward relative to the solder paste nozzle 200.

According to an example of the present application, the diameter of the end 202 of the solder paste nozzle 200 is smaller than the diameter of the other parts of the solder paste nozzle 200, so as to form a stepped face 250 at the position where the end 202 meets the other parts of the solder paste nozzle 200. The stepped face 250 as described above can facilitate the assembly of the solder paste nozzle 200 onto the worktable 300, which will be described in detail with reference to Fig. 4A.

Of course, the main body 210 of the solder paste nozzle 200 may have other shapes as long as the head 230 thereof is cylindrical. When the main body 210 is cylindrical, the diameter of the head 230 of the main body 210 may not be increased. In addition, the size of the end 202 of the main body 210 may be the same as that of other parts of the main body 210. These are all within the scope of protection of the present application.

Still as shown in Figs. 2A-2C, the through-hole 218 of the nozzle has an inlet 207 and an outlet 209. The inlet 207 is provided at the head 230, while the outlet 209 is provided at the end 202. Solder paste enters from the inlet 207 of the through-hole 218 of the nozzle and is discharged from the outlet 209 thereof.

The end 202 is provided with two inclined faces 221.1 and 221.2. The two inclined faces 221.1 and 221.2 are symmetrically disposed with respect to the through-hole 218. Both inclined faces 221.1 and 221.2 extend through the through-hole 218, but the two inclined faces 221.1 and 221.2 do not intersect, thus avoiding a sharp corner between the two inclined faces. The arrangement of the inclined faces helps to guide the gas flow to cut off the residual solder paste at the outlet 209 of the end 202, such that the solder paste drops at a suitable position, which will be described in detail below. It should be noted that the number of inclined faces of the end 202 may also be set to one or more than two, which are all within the scope of protection of the present application.

Figs. 3A and 3B respectively show perspective views of the worktable 300 of the present application from two angles of view, and Fig. 3C is a partial cross-sectional view of the worktable 300 of the present application on which the solder paste nozzle 200 of the present application is mounted. As shown in Figs. 3A-3C, the worktable 300 is provided with an opening 303 and two air ducts 410.1 and 410.2. The two air ducts 410.1 and 410.2 are symmetrically disposed with respect to the opening 303. The opening 303 extends through the worktable 300 for accommodating the end 202 of the solder paste nozzle 200. The air ducts 410.1 and 410.2 are used to guide the gas in the clean gas source (not shown) toward the end 202 of the solder paste nozzle 200 accommodated in the opening 303, so as to cut (or remove) the residual solder paste at the end 202 by the gas.

Specifically, the opening 303 is U-shaped, so that the inner side wall 313 of the opening 303 comprises left and right inner side walls 301.1 and 301.2 opposite each other and a rear inner side wall 302 located between the left and right inner side walls 301.1 and 301.2. The left and right inner side walls 301.1 and 301.2 of the opening 303 and a lower part 314 of the rear inner side wall 302 are gradually inclined away from the center of the opening.

The two air ducts 410.1 and 410.2 comprise air duct inlets 308.1 and 308.2 and air duct outlets 309.1 and 309.2, respectively. The air duct inlets 308.1 and 308.2 are respectively disposed in an outer wall of the worktable to facilitate communication with the external gas source. The air duct outlets 309.1 and 309.2 are respectively disposed in the left and right inner side walls 301.1 and 301.2 of the opening 303 of the worktable and are located on the inclined lower part 314 of the left and right inner side walls 301.1 and 301.2. The air duct outlets 309.1 and 309.2 are flat, such that the gas flow flowing out of the air duct outlets 309.1 and 309.2 is sharper and thus the residual solder paste can be easily removed.

As shown in Fig. 3C, the air ducts 410.1 and 410.2 each comprises a first air duct part 425.1, 425.2 and a second air duct part 426.1, 426.2. The first air duct parts 425.1 and 425.2 are connected to the gas source through the air duct inlets 308.1 and 308.2, respectively, and the second air duct parts 426.1 and 426.2 are connected to the first air duct parts 425.1 and 425.2 and are connected to the air duct outlets 309.1 and 309.2, respectively. The second air duct parts 426.1 and 426.2 are inclined downward from connection ends connected to the first air duct parts 425.1 and 425.2, such that the direction of gas flow from the air duct outlets 309.1 and 309.2 is in a downward inclined direction. Of course, the air ducts 410.1 and 410.2 can also be designed to be generally inclined downward from the inlet toward the outlet, and such a design can also provide gas flow flowing out in a downward inclined direction.

In addition, the second air duct parts 426.1 and 426.2 are thinner than the first air duct parts 425.1 and 425.2, so that the gas flowing from the first air duct parts 425.1 and 425.2 into the second air duct parts 426.1 and 426. is accelerated, thereby forming a sharper air knife at the air duct outlets 309.1 and 309.2. Of course, it is also possible to set the thickness of the second air duct parts 426.1 and 426.2 and the first air duct parts 425.1 and 425.2 to be the same. In addition, the clean gas can be compressed gas so as to increase the gas flow rate, thereby being beneficial to making the air knife sharper.

In the embodiment shown in Figs. 3A-3C, the air duct inlets 308.1 and 308.2 are disposed in an outer side wall of the worktable, but in other embodiments, the air duct inlets 308.1 and 308.2 can also be disposed at other parts of the worktable, so long as it is convenient to connect the gas source.

In the embodiment shown in Figs. 3A-3C, two air ducts are provided for providing gas flow to the two inclined faces 221.1 and 221.2 at the end 202 of the solder paste nozzle 200, respectively. In other embodiments, the number of air ducts may be other numbers as long as it matches the number of the inclined faces at the end of the solder paste nozzle.

In addition, although in the above embodiment, the opening 303 of the worktable 300 is recessed inward from one side of the worktable to form a U-shaped groove, the opening 303 may also be a through-hole penetrating through the worktable 300.

Fig. 4A is a cross-sectional view of the solder paste nozzle 300 shown in Fig. 2A assembled in a solder paste tank 107 and assembled on the worktable 300 shown in Fig. 3A. Fig. 4B is an enlarged partial view of part F in Fig. 4A. Next, the process of the solder paste nozzle 200 cooperating with the worktable 300 to remove the residual solder paste near the outlet of the solder paste nozzle will be explained with reference to Figs. 4A and 4B.

As shown in Figs. 4A and 4B, the head 230 of the assembled solder paste nozzle 200 is inserted into the solder paste tank 107, and the solder paste nozzle 200 is assembled on the worktable 300, such that the solder paste nozzle 200 and the solder paste tank 107 are carried by the worktable 300. When the solder paste nozzle 200 is loaded into the solder paste tank 107 containing solder paste, a seal cap (not shown) of a tank opening 171 of the solder paste tank 107 is first removed, and then the nozzle head 230 of the solder paste nozzle is inserted into the solder paste tank 107 from the tank opening 171 of the solder paste tank 107. The vicinity of the tank opening 171 of the solder paste tank 107 is not filled with solder paste, thus leaving a mounting space for the solder paste nozzle 200. During solder addition, when the solder paste tank 107 is pressed downward, the solder paste tank 107 is squeezed and thus moves downward relative to the solder paste nozzle 200. Since the diameter of the head 230 of the solder paste nozzle 200 matches the inner diameter of the solder paste tank 107, the solder paste in the solder paste tank 107 above the head 230 of the solder paste nozzle 200 is squeezed into and discharged from the through-hole 218 of the solder paste nozzle.

As shown in Figs. 4A and 4B, when the solder paste nozzle 200 is mounted in place on the worktable 300, the end 202 of the solder paste nozzle 200 is inserted into the opening 303 of the worktable 300, and the stepped face 250 of the solder paste nozzle 200 abuts against the top of the worktable 300. The two inclined faces 221.1 and 221.2 on the end 202 of the solder paste nozzle 200 face the two air duct outlets 309.1 and 309.2 of the worktable 300, respectively.

When the solder addition operation is completed, the external gas source is activated to allow the gas flow to flow through the worktable air ducts 410.1 and 410.2 and to flow out from the air duct outlets 309.1 and 309.2 toward the two inclined faces 221.1 and 221.2 of the end 202 of the solder paste nozzle 200, so that the solder paste remaining at the end 202 of the solder paste nozzle 200 can be quickly removed without dropping to an undesired position.

In order to remove solder paste better, as shown in Fig. 4B, comparing the included angle a between the second air duct part 426.2 of the worktable and the horizontal plane L with the included angle β between the inclined face 212.2 of the nozzle end 202 and the horizontal plane L, a < β, such that the inclined angle of the gas flow blown out from the air duct outlet is smaller than the inclined angle of the inclined face of the nozzle end. When a is slightly less than β, the gas flow can enter the through-hole 218 at the end from the inclined faces 221.1 and 221.2 at the end of the nozzle. Therefore, the gas flow can not only remove the residual solder paste hanging from the outlet of the nozzle through-hole 218, but can also remove the residual solder paste on the inner wall of the through-hole 218 at the end. Of course, the purpose of the present application can also be achieved by making a = β, that is, the residual solder paste at the outlet of the through-hole of the nozzle can be removed, wherein the angle of β is between 10° and 40° and may include 10° and 40°.

In addition, when the solder paste nozzle 200 is mounted in place in the worktable

300, the air duct outlets 309.1 and 309.2 are set higher than the nozzle outlets on the inclined faces 221.1 and 221.2 of the end of the nozzle. Moreover, the width of the air duct outlets 309.1 and 309.2 is set to be not less than the width of the outlet 209 of the through-hole 218, such that the gas flow and the inclined faces of the end 202 have sufficient contact area, which is more favorable for removing the residual solder paste.

In addition, the lower part 314 of the inner side wall of the opening 303 of the worktable 300 is designed to be inclined outward, so that the air duct outlet located on the lower part of the inner side wall can be farther away from the nozzle outlet, thus avoiding the risk that the air duct outlet is blocked by solder paste.

The worktable and the solder paste nozzle provided by the present application cooperate with each other, so that residual solder paste at the outlet of the nozzle can be removed more thoroughly. Moreover, since the end of the solder paste nozzle has a downward inclined face and the gas flow is also configured to flow obliquely downward, the residual solder paste cut off by the gas flow can be guided to fall below the nozzle at a position where the solder paste needs to be dispensed without being dispersed to other unwanted positions.

This specification uses examples to disclose the present application, one or more of which are illustrated in the accompanying drawings. Each example is provided for the purpose of explaining the present application and is not intended to limit the present application. In fact, it will be obvious to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope or spirit of the present application. For example, the features illustrated or described as part of one embodiment may be used with another embodiment to obtain a further embodiment. Therefore, it is intended that the present application covers modifications and variations within the scope of the appended claims and the equivalents thereof.