JP7113164B2 - printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus that prints a paste on a printing material by ejecting paste from a print head onto a mask that is in contact with the printing material.

2. Description of the Related Art Conventionally, there has been known a printing apparatus that supplies a paste such as solder to a mask brought into contact with an object to be printed such as a substrate to print the paste on the object to be printed. Generally, the printing apparatus is of a type in which paste is supplied onto the mask manually or the like, and then the pattern openings of the mask are filled with the paste by sliding a squeegee over the mask. It is also known to have a print head that ejects and pushes directly into the substrate. The print head is provided with a pair of blades facing each other at the lower edges of a casing containing a paste. When the paste is pressed by a pressure means, the paste is extruded and discharged from the discharge port in the gap between the pair of blades. is discharged.

In the print head configured as described above, the holding force for preventing the unpressurized paste from leaking out of the ejection port due to its own weight is obtained from the surface tension of the paste itself at the ejection port. For this reason, although the gap between the lower edges of the pair of blades is set to be extremely small, the paste with low viscosity has insufficient surface tension and leaks out from the ejection port. When the paste leaks, the paste in the print head becomes insufficient, and the supply of the paste to the printed material becomes insufficient, which may degrade the printing quality. As a countermeasure against such inconvenience, a print head has been devised in which a plate member having a large number of small-diameter holes formed therein is provided at a position immediately before the ejection port (for example, Patent Document 1 below). In this print head, the paste in a non-pressurized state is held by its own surface tension generated at the positions of the holes. This makes it easier to prevent the paste from leaking.

Japanese Patent Application Laid-Open No. 2006-168028

However, even with a print head having the plate member described above, if the viscosity of the paste is extremely low, the paste holding power may be insufficient, and the paste may leak from the ejection ports.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a printing apparatus capable of preventing the paste from leaking due to its own weight even when the viscosity of the paste is extremely low.

A printing apparatus according to the present invention is a printing apparatus that prints paste on an object to be printed through pattern openings provided in the mask by ejecting and supplying paste from a print head onto a mask that is in contact with the object to be printed, The print head includes a casing having a paste containing portion for containing the paste and a paste passage extending downward from the paste containing portion; A pair of blades provided in the casing so as to be, pressurizing means for pressurizing the paste in the paste container and ejecting the paste extruded into the paste passage from the ejection port, and penetrating in the thickness direction a plate-like valve member having cuts and provided at a position above the pair of blades and blocking the paste passage, wherein the valve member is pushed into the paste passage by the pressurizing means. The pair of blades are provided in a downwardly tapering posture by bending and deforming according to the pressing force received from the paste to open and close the cut to allow or block the passage of the paste, and the valve The member is flexurally deformed above the pair of blades and within a range where the blades are not deformed by interfering with the blades .

According to the present invention, even if the viscosity of the paste is extremely low, it is possible to prevent leakage due to the weight of the paste.

Schematic configuration diagram of a printing apparatus according to an embodiment of the present invention 1 is a perspective view of a print head included in a printing apparatus according to an embodiment of the invention; FIG. (a) and (b) are side cross-sectional views of a print head included in a printing apparatus according to an embodiment of the present invention. 1 is an exploded perspective view of a print head included in a printing apparatus according to an embodiment of the present invention; FIG. 1 is an exploded side view of a print head included in a printing apparatus according to an embodiment of the present invention; FIG. (a) and (b) are sectional side views for explaining the operation of the valve member of the print head provided in the printing apparatus according to the embodiment of the present invention. (a) and (b) are diagrams for explaining the operation of the printing apparatus according to one embodiment of the present invention. (a) and (b) are diagrams for explaining the operation of the printing apparatus according to one embodiment of the present invention. (a) and (b) are side cross-sectional views of the print head showing the mounting state of the valve member to the casing in the modification of the embodiment of the present invention. (a), (b), (c), and (d) are diagrams showing modified examples of notches formed in the valve member of the print head of the printing apparatus according to the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a printer 1 according to an embodiment of the invention. The printing apparatus 1 is an apparatus for printing a paste Pst such as solder on the surface of a substrate KB, which is an object to be printed. A controller 16 is provided. In this embodiment, for convenience of explanation, the direction perpendicular to the paper surface of FIG. 1 is the X-axis direction, the horizontal direction of the paper surface of FIG. 1 is the Y-axis direction, and the vertical direction of the paper surface of FIG. 1 is the Z-axis direction.

In FIG. 1, the substrate holder 11 holds the substrate KB in such a manner that the upper surface of the substrate KB is exposed. A large number of electrodes (not shown) are provided on the upper surface of the substrate KB. The substrate holding portion moving mechanism 12 moves the substrate holding portion 11 holding the substrate KB in the horizontal direction (XY plane direction) and the vertical direction (Z-axis direction). The mask 13 is composed of a plate-like member, and is provided with a large number of pattern openings 13H corresponding to the electrodes of the substrate KB.

The print head 14 has a function of ejecting the paste Pst downward, and the head moving mechanism 15 moves the print head 14 in the Y-axis direction and the Z-axis direction. The control device 16 controls the holding operation of the substrate KB by the substrate holding unit 11, the movement operation of the substrate holding unit 11 by the substrate holding unit moving mechanism 12, the ejection operation of the paste Pst by the print head 14, and the movement of the print head 14 by the head moving mechanism 15. Each control of movement operation is performed.

2 and 3A and 3B, the print head 14 comprises a casing 21 moved by the head moving mechanism 15, a pair of blades 22 attached to the casing 21, a pressure cylinder 23 and a valve member 24. It has The casing 21 has a paste containing portion 31 containing the paste Pst and a paste passage 32 connected to the lower portion of the paste containing portion 31 . A paste cartridge 33 containing a paste Pst is replaceably attached to the paste container 31 .

4 and 5, the lower portion of the casing 21 is provided with two sloped portions 21M that taper downward. Each of the pair of blades 22 has a shape extending in the X-axis direction, and is attached to the casing 21 so that the upper half of the blade 22 extends along each of the two sloped portions 21M (thus, in a downwardly tapering posture). It is The lower edges 22E of the pair of blades 22 face each other in the Y-axis direction, and a gap is formed between the two lower edges 22E.

Each blade 22 is pressed against the slope portion 21M by a blade pressing member 41 extending in the X-axis direction, and fixed to the casing 21 by a mounting screw 42 screwed into the slope portion 21M. Each blade 22 is thus detachable from the casing 21 .

2 and 3(a), (b), the pressurizing cylinder 23 has a piston rod 23R directed downward, and a pressurizing plate 23P is attached in a horizontal posture to the lower end of the piston rod 23R. The pressure cylinder 23 operates the piston rod 23R to move the pressure plate 23P up and down to pressurize the paste Pst in the paste container 31 (the paste Pst in the paste cartridge 33 installed in the paste container 31). , the paste Pst in the paste container 31 is pushed out into the paste passage 32 .

The paste Pst in the paste container 31 pressurized by the pressurizing cylinder 23 passes through the paste passage hole 21H (FIG. 3A, ( b)) into the paste passage 32 . A gap between the lower edges 22E of the pair of blades 22 is located below the paste passage 32, and the gap serves as a discharge port 14T for the paste Pst from the paste passage 32. As shown in FIG.

Thus, in the present embodiment, the pair of blades 22 are provided in the casing 21 so that the gap between the opposed lower edges 22E serves as the discharge port 14T for the paste Pst from the paste passage 32. As shown in FIG.

In FIG. 4, the valve member 24 is composed of a rectangular plate member extending in the direction in which the blade 22 extends (the X-axis direction). The valve member 24 has two long sides facing each other in the direction (Y-axis direction) in which the pair of blades 22 face each other. Thus, it is provided at a position blocking the paste passage 32 (FIGS. 2, 3A, 3B and 5). Here, the valve member 24 is attached to the casing 21 in a so-called pin-supported state in which rotation of the end portion is permitted.

3(a), (b) and 4, the valve member 24 has a notch 25 extending in the longitudinal direction (that is, the X-axis direction) and penetrating in the thickness direction (the Z-axis direction). Here, the cut 25 is provided to extend linearly in the direction in which the blade 22 extends (the X-axis direction).

The paste Pst that reaches the paste passage 32 from the paste containing portion 31 through the paste passage hole 21H provided in the partition wall 21D is supported by the valve member 24 (FIG. 3(b)). When the pressure cylinder 23 does not pressurize the paste Pst in the paste container 31 (the paste Pst in the paste cartridge 33), the valve member 24 maintains a substantially flat plate shape and the cut 25 is closed. state to block the passage of the paste Pst (FIG. 6(a)).

On the other hand, when the paste Pst in the paste container 31 is pressurized by the pressurizing cylinder 23, the valve member 24 is bent downward according to the pressing force received from the paste Pst, and the notch 25 opens to release the paste Pst. Passage is permitted (FIG. 6(b)). Therefore, when the paste Pst in the paste cartridge 33 is pressurized by the pressure cylinder 23, the paste Pst is ejected from the ejection port 14T.

Here, the degree of opening of the notch 25 (opening degree) when the valve member 24 is bent is determined by the amount of pressure received by the valve member 24 from the paste Pst in the paste passage 32 (the pressurized cylinder via the paste Pst in the paste passage 32). The larger the pressing force received from 23, the larger the flow rate of the paste Pst to be passed. Therefore, the larger the pressing force received from the pressurizing cylinder 23 is, the larger the discharge amount of the paste Pst becomes.

In this embodiment, as described above, the pair of blades 22 are attached in a posture that tapers downward. A portion of the valve member 24 having the largest downward displacement (the portion where the notch 25 is provided) is positioned above the discharge port 14T. Therefore, the downwardly bent valve member 24 does not interfere with the pair of blades 22 , and the bending of the valve member 24 (and thus the opening of the cut 25 ) is not restricted by the blades 22 . There is no risk of deformation due to application of a bending load (FIG. 6(b)).

When the pressurizing cylinder 23 stops pressurizing the paste Pst in the paste cartridge 33 from such a state of discharging the paste Pst, the pressing force acting on the valve member 24 is removed. As a result, the valve member 24 returns to its original flat plate shape, and the notch 25 is closed. Therefore, the paste Pst in the paste container 31 does not pass through the notch 25 (that is, through the valve member 24) and does not leak due to its own weight (FIG. 6(a)).

As described above, in the present embodiment, the valve member 24 is flexurally deformed according to the pressing force received from the paste Pst extruded into the paste passage 32 by the pressurizing cylinder 23, thereby opening and closing the notch 25 to release the paste Pst. It allows or prevents passage.

As described above, the notch 25 provided in the valve member 24 opens when a pressing force acts on the valve member 24, but the minimum pressing force at which the notch 25 begins to open varies depending on various conditions. Here, various conditions vary depending on, for example, the vertical and horizontal dimensions and thickness of the valve member 24, the length of the notch 25, the method of supporting the ends of the valve member 24, the material of the valve member 24, the rigidity, and the like. Therefore, under these various conditions, the valve member 24 is manufactured by examining in advance the relationship between the pressing force of the paste Pst by the pressurizing cylinder 23 and the degree of opening of the notch 25 (opening degree).

When the paste Pst is printed on the substrate KB by the printing apparatus 1 configured as described above, first, the substrate holding unit 11 receives and holds the substrate KB conveyed by a substrate conveying device (not shown). Then, the substrate holder moving mechanism 12 moves the substrate holder 11 to bring the substrate KB into contact with the lower surface of the mask 13 so that the electrodes of the substrate KB and the pattern openings 13H of the mask 13 are aligned.

After the substrate KB comes into contact with the mask 13, the head moving mechanism 15 lowers the print head 14 to bring the lower edges 22E of the pair of blades 22 into contact with the upper surface of the mask 13 (FIG. 7(a)). Then, the head moving mechanism 15 moves the print head 14 in the horizontal direction (Y-axis direction) with respect to the mask 13 and slides the pair of blades 22 on the mask 13 . During this time, the print head 14 ejects the paste Pst from the ejection port 14T, supplies the paste Pst to the upper surface of the mask 13, and fills the pattern openings 13H with the paste Pst (FIG. 7B).

When all the pattern openings 13H provided in the mask 13 are filled with the paste Pst, the movement of the print head 14 is stopped and the pressure of the paste Pst by the pressure cylinder 23 is stopped. When the pressurization by the pressurizing cylinder 23 is stopped, the valve member 24 returns to the flat plate shape, the notch 25 is closed, and the paste Pst is not supplied (FIG. 8(a)).

When the paste Pst is not supplied, the head moving mechanism 15 raises the print head 14 to separate the lower edge 22E of each of the pair of blades 22 from the upper surface of the mask 13 (FIG. 8(b)). Then, the substrate holding portion moving mechanism 12 lowers the substrate holding portion 11 to separate the substrate KB from the mask 13 (plate separation). As a result, the paste Pst remains on each electrode of the substrate KB, and the paste Pst is printed on the substrate KB. After the paste Pst is printed on the substrate KB in this manner, the substrate KB is removed from the substrate holding unit 11 and transported to the outside of the printer 1 by the substrate transporting device (not shown).

As described above, in the printing apparatus 1 according to the present embodiment, the plate-like valve member 24 provided at a position blocking the paste passage 32 of the print head 14 has the cut 25 penetrating in the thickness direction. When the paste Pst is pressurized by the pressurizing cylinder 23, the valve member 24 is flexurally deformed to open the notch 25 so that the paste Pst can be discharged. Since the notch 25 is closed without being deformed, passage of the paste Pst is blocked, and leakage of the paste Pst due to its own weight is prevented.

In the above-described embodiment, the valve member 24 is attached to the casing 21 by a pin support that allows rotation of the end portion. It may be attached to the casing 21 by supports. When both ends of the valve member 24 are fixedly supported, as shown in FIG. 9A, lip portions 24L having an inclination corresponding to the slope portion 21M of the casing 21 are provided at both ends of the valve member 24. . Then, each lip portion 24L is sandwiched between the slope portion 21M and the blade pressing member 41 so that the valve member 24 is fixedly supported by both lip portions 24L (FIG. 9(b)).

When both ends of the valve member 24 are fixedly supported, compared with the case where both ends are supported by pins, the amount of deflection for the same pressing force is smaller, so the opening of the notch 25 is also smaller. Therefore, by using this relationship, it becomes possible to finely adjust the relationship between the pressing force of the paste Pst by the pressurizing cylinder 23 and the opening degree of the notch 25 .

Further, in the above example, the notch 25 of the valve member 24 is provided so as to extend linearly in the direction in which the blade 22 extends (the Y-axis direction). Various modifications as shown in (c) and (d) are possible. Here, FIGS. 10A and 10C are examples in which a plurality of linear cuts 25 are provided side by side in the direction in which the blade 22 extends. 10(b) and 10(c) are examples in which an auxiliary cut portion 26 extending in a direction different from the direction in which the cut 25 extends is provided at the end of the cut 25. As shown in FIG.

As in the example shown in FIGS. 10(a) and 10(c), when a plurality of cuts 25 are provided in the direction in which the blade 22 extends, the length of one cut 25 is the length of the above-described embodiment. Since it is shorter than in the case of the above-described embodiment, a larger pressing force is required to open the notch 25 than in the case of the above-described embodiment. In other words, even if the pressure is the same, the discharge amount of the paste Pst is reduced. Therefore, by using this relationship, it becomes possible to finely adjust the relationship between the pressing force of the paste Pst by the pressurizing cylinder 23 and the opening degree of the notch 25 .

As in the example shown in FIGS. 10(b) and 10(c), when the auxiliary cut portion 26 is provided at the end of the cut 25, even if the applied pressure is the same, the auxiliary cut portion 26 is provided. The opening degree of the cut 25 is increased and the discharge amount of the paste Pst is increased as compared with the case where the cutout 25 is not formed. Therefore, by using this relationship, it becomes possible to finely adjust the relationship between the pressing force of the paste Pst by the pressurizing cylinder 23 and the opening degree of the notch 25 .

FIG. 10(d) belongs to an example in which a plurality of cuts 25 are provided side by side in the direction in which the blade 22 extends. This is an example. In the example of FIGS. 10A and 10C, the positions on the X-axis of the ends of adjacent cuts 25 are spaced apart in the X-axis direction. For this reason, there may be a position where the supply of the paste Pst in the X-axis direction is interrupted, but in the example of FIG. Therefore, the supply position of the paste Pst in the X-axis direction is not interrupted, and the paste Pst can be supplied to the mask 13 with little unevenness.

As described above, in the printing apparatus 1 according to the present embodiment, the plate-like valve member 24 having the cut 25 penetrating in the thickness direction is provided at a position blocking the paste passage 32 provided in the print head 14. The valve member 24 is flexurally deformed according to the pressing force received from the paste Pst extruded into the paste passage 32 by the pressurizing cylinder 23, thereby opening and closing the notch 25 to allow or block the passage of the paste Pst. It's like Therefore, when the pressurizing cylinder 23 does not pressurize the paste Pst in the paste container 31, the notch 25 is closed and the passage of the paste Pst is prevented. Also, leakage of the paste Pst due to its own weight can be prevented. In addition, this makes it difficult for the paste shortage state in the print head 14 to occur, and it is possible to avoid a situation in which the print quality is degraded due to the paste Pst supply shortage.

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above. For example, in the above-described embodiment, the paste cartridge 33 is installed in the paste container 31 to contain the paste Pst in the paste container 31. The paste Pst may be accommodated in the paste accommodation portion 31 by directly supplying it to the accommodation portion 31 .

Further, in the above-described embodiment, the pressurizing means for pressurizing the paste Pst contained in the paste container 31 is a cylinder (pressurizing cylinder 23) for raising and lowering the pressurizing plate 23P. It may be a motor or the like. Furthermore, the target on which the paste Pst is printed is not limited to the substrate KB, and may be another target to be printed.

To provide a printer capable of preventing leakage of paste due to its own weight even when the viscosity of the paste is extremely low.

REFERENCE SIGNS LIST 1 printing device 13 mask 13H pattern opening 14 print head 14T discharge port 21 casing 22 blade 22E bottom edge 23 pressure cylinder (pressure means)
24 valve member 25 notch 26 auxiliary notch 31 paste containing portion 32 paste passage KB substrate (printing material)
Pst paste

Claims (5)

A printing apparatus for printing a paste on a substrate to be printed through pattern openings provided in the mask by ejecting and supplying the paste from a print head onto the mask in contact with the substrate to be printed,
The print head is
a casing comprising a paste containing portion for containing the paste and a paste passage connected to the lower portion of the paste containing portion;
a pair of blades provided on the casing so that the gap between the opposed lower edges serves as a paste discharge port from the paste passage;
pressurizing means for pressurizing the paste in the paste container and for discharging the paste extruded into the paste passage from the discharge port;
a plate-shaped valve member having a cut that penetrates in the thickness direction and provided at a position above the pair of blades and blocking the paste passage,
the valve member is flexurally deformed according to the pressing force received from the paste extruded into the paste passage by the pressurizing means, thereby opening and closing the notch to permit or prevent passage of the paste ;
The pair of blades are provided in a posture that tapers downward,
The printing apparatus according to claim 1, wherein the valve member is above the pair of blades and deforms by bending within a range that does not interfere with the blades and deform the blades . When the pressurizing means pressurizes the paste in the paste container, the valve member is flexurally deformed so as to open the cut to allow the paste to pass through, and the pressurizing means causes the paste in the paste container to pass through. 2. The printing apparatus according to claim 1, wherein the cut is closed to prevent passage of the paste when the is not pressurized. 3. A printing apparatus according to claim 1, wherein said cut extends in the direction in which said blade extends. 4. The printing apparatus according to claim 1, wherein a plurality of said cuts are provided side by side in the direction in which said blade extends. 5. The printing apparatus according to claim 1, further comprising an auxiliary cut portion extending in a direction different from the direction in which said cut extends at the end of said cut.

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