Dispenser

Abstract

To provide a dispenser that can accurately adjust a height position in a vertical direction of an actuator while making shearing stress and flexural stress hardly act on the actuator at that time, and can improve responsiveness of a displacement expansion mechanism relative to high-speed driving of the actuator.SOLUTION: A dispenser includes: a nozzle 32 for discharging a liquid material; a supply passage 33 for supplying the liquid material to the nozzle 32; a tappet 34 whose tip portion reciprocates in a vertical direction inside the supply passage 33; a displacement expansion mechanism 14 for giving displacement to the tappet 34; an actuator 15 for applying displacement to the displacement expansion mechanism 14; and a height adjustment mechanism 16 for adjusting a height position of the actuator 15. The height adjustment mechanism 16 comprises a differential screw mechanism mounted on a main frame 11 of a dispenser body 1, and a lower surface of a slide member sliding in the vertical direction in the differential screw mechanism, and an upper surface of an upper end portion of the actuator 15 are joined together.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a dispenser for discharging a liquid material.

Background Art

[0002] Dispensers for discharging liquid materials such as water, oil, and resin are used in various fields such as semiconductor processes and medical fields. Particularly in semiconductor processes, dispensers are widely used in underfill processes, and are also widely used for filling the inside of semiconductor element packages with resin. In the manufacturing process of LED elements, dispensers are used in the process of applying a fluorescent liquid in which a fluorescent substance and resin are mixed to an LED chip.

[0003] As such a dispenser for discharging a liquid material, a type that discharges the liquid material from a nozzle by the reciprocating motion of a tappet is known. In Patent Document 1, a dispenser (liquid coating device) is disclosed that includes a nozzle for discharging a liquid material, a supply passage for supplying the liquid material to the nozzle, a tappet (plunger) whose tip reciprocates in the vertical direction within the supply passage, a displacement amplification mechanism for applying displacement to the tappet (plunger), and an actuator for applying displacement to the displacement amplification mechanism. Patent Document 1 also discloses using a piezo element (piezoelectric element) as the actuator. Also, Patent Document 2 discloses using a piezo element (piezo stack) as the actuator. Patent Document 2 also discloses adjusting the vertical height position of the piezo element (piezo stack) by a screwing operation.

[0004] Here, in order to accurately control the discharging operation of the liquid material by the dispenser, it is necessary to accurately adjust the vertical height position of the actuator. In this regard, in the prior art, as described above, it is common to adjust the vertical height position of the actuator by a screwing operation, but it is difficult to accurately adjust the vertical height position of the actuator by a simple screwing operation. In addition, piezoelectric elements commonly used in actuators have the disadvantage of being particularly vulnerable to shear stress, bending stress, and tensile stress. Therefore, when adjusting the vertical height position of an actuator including a piezoelectric element by a screwing operation, shear stress and bending stress associated with the screwing operation act on the piezoelectric element, leading to problems such as a decrease in the operating accuracy of the actuator or a shortening of its lifespan. Furthermore, in Patent Documents 1 and 2, since the entire weight of the actuator is applied to the lever member constituting the displacement amplification mechanism, there is also a problem that the responsiveness of the displacement amplification mechanism (lever member) to the high-speed driving of the actuator is not sufficient.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to provide a dispenser that can accurately adjust the vertical height position of an actuator, while making it difficult for shear stress and bending stress to act on the actuator, and further improving the responsiveness of the displacement amplification mechanism to the high-speed driving of the actuator.

Means for Solving the Problems

[0007] According to one aspect of the present invention, the following dispenser is provided. A dispenser comprising a nozzle for discharging a liquid material, a supply passage for supplying the liquid material to the nozzle, a tappet whose tip reciprocates in the vertical direction within the supply passage, a displacement amplification mechanism for applying displacement to the tappet, an actuator for applying displacement to the displacement amplification mechanism, and a height adjustment mechanism for adjusting the vertical height position of the actuator, The actuator includes a piezo stack in which piezo elements are stacked, The height adjustment mechanism consists of a differential screw mechanism attached to the frame of the dispenser body. In the differential screw mechanism, the lower surface of a slide member that slides in the vertical direction is joined to the upper surface of the upper end portion of the actuator. Dispenser.

Advantages of the Invention

[0008] According to the present invention, a differential screw mechanism is adopted as a height adjustment mechanism for adjusting the vertical height position of the actuator, and the lower surface of the slide member that slides in the vertical direction in the differential screw mechanism is joined to the upper surface of the upper end portion of the actuator. Therefore, the vertical height position of the actuator can be accurately adjusted, and at this time, shear stress and bending stress are less likely to act on the actuator. Furthermore, according to the present invention, the differential screw mechanism, which is the height adjustment mechanism, is attached to the frame of the dispenser body, and moreover, the lower surface of the slide member of this differential screw mechanism is joined to the upper surface of the upper end portion of the actuator. Therefore, the actuator is supported by the differential screw mechanism, which is the height adjustment mechanism. As a result, the self-weight of the actuator is less likely to be applied to the displacement amplification mechanism, and the responsiveness of the displacement amplification mechanism to the high-speed driving of the actuator can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] FIG. 1 shows a perspective view of a dispenser according to an embodiment of the present invention as viewed from one side. FIG. 2 shows a longitudinal sectional view of the dispenser of FIG. 1. The dispenser X of the present embodiment includes a dispenser main body 1 and a nozzle block 3 detachably attached to the dispenser main body 1.

[0011] The dispenser main body 1 has a shape in which both side surfaces of the main frame 11 are covered with covers 111, and various members described later are installed inside. On the upper surface portion of the main frame 11, there are provided a power supply terminal 12 for supplying power to each member installed in the main frame 11, and an air introduction portion 13A and an air discharge portion 13B for introducing and discharging cooling air into the main frame 11.

[0012] The nozzle block 3 is detachably attached to the lower surface side of the main frame 11. The nozzle block 3 includes a block body 31, a nozzle 32 for discharging a liquid material, a supply passage 33 for supplying the liquid material to the nozzle 32, and a tappet 34 whose tip reciprocates in the vertical direction within the supply passage 33. The nozzle 32 is attached to a nozzle mounting portion 311 on the lower surface side of the block body 31 by a nozzle nut 321. The supply passage 33 is formed within the block body 31 so as to communicate a liquid material introduction portion 312 provided on the upper surface portion of the block body 31 with the nozzle 32. Note that the liquid material is introduced into the liquid material introduction portion 312 from a tank (not shown) for storing the liquid material. The tappet 34 is held by a tappet holder 341, and the tappet holder 341 holding the tappet 34 is mounted in a tappet mounting hole 112 provided in the lower surface portion of the main frame 11 of the dispenser body 1. The upper end portion of the tappet 34 held by the tappet holder 341 protrudes into the main frame 11. Further, a first biasing member 342 that elastically biases the tappet 34 upward is incorporated in the tappet holder 341. Typically, a compression coil spring can be used as the first biasing member 342. In this embodiment, the nozzle block 3 is detachably mounted on the dispenser body 1, but the configuration of the nozzle block 3 may be incorporated into and integrated with the dispenser body 1.

[0013] As shown in FIG. 2, the dispenser body 1 includes, within the main frame 11, a displacement amplification mechanism 14 that gives displacement to the tappet 34, an actuator 15 that gives displacement to the displacement amplification mechanism 14, and a height adjustment mechanism 16 that adjusts the vertical height position of the actuator 15. The displacement amplification mechanism 14 includes a fulcrum member 141 and a lever member 142. The fulcrum member 141 has a cylindrical shape and is fixed to the main frame 11. The lever member 142 has a fulcrum portion 142a that contacts the fulcrum member 141, an action point portion 142b that contacts the upper end portion of the tappet 34, and a force point portion 142c that contacts the lower end portion of the actuator 15. In this embodiment, the force point portion 142c is between the fulcrum portion 142a and the action point portion 142b. Further, a second biasing member 143 that elastically biases this end portion downward is disposed at the end portion of the lever member on the side opposite to the action point portion 142b. Typically, a compression coil spring can be used as the second biasing member 143. Thus, the displacement amplification mechanism 14 is a "lever mechanism" and has the function of amplifying the amount of displacement in the vertical direction of the tappet 34 more than the amount of displacement in the vertical direction of the actuator 15.

[0014] The actuator 15 is used as a drive source for applying vertical displacement to the displacement amplification mechanism 14, and as a result, reciprocatingly operating the tappet 34 in the vertical direction, and in the present invention, it is configured to include a piezo element. Fig. 3 shows a perspective view of the main part of the actuator 15 used in the present embodiment. In the present embodiment, the actuator 15 includes a piezo stack 151 in which piezo elements are laminated, and a preloading member 152 that applies preload to the piezo stack 151. The preloading member 152 can be configured by a tension spring.

[0015] Next, the height adjustment mechanism 16, which is one of the features of the present invention, will be described. Fig. 4 shows an enlarged cross-sectional view of the main part including the height adjustment mechanism 16. The height adjustment mechanism 16 consists of a differential screw mechanism. In the present embodiment, the differential screw mechanism is attached to the main frame 11, and includes a main screw 161 screwed into a female screw part (nut) 113 provided on the main frame 11, a slide member 162 having a sub-screw 162a screwed inside the main screw 161, and a guide pin 163. Here, the guide pin 163 has a function of preventing rotation so that the sub-screw 162a does not rotate, and a function of guiding the slide member 162 to slide in the vertical direction. That is, the slide member 162 slides in the vertical direction without rotating in combination with the above-described functions of the guide pin 163. Further, the lower surface of the slide member 162 has a shape including a concave spherical surface 162b. In this differential screw mechanism, if the pitch of the main screw 161 is P1 and the pitch of the sub-screw 162a is P2, then P1 > P2. On the other hand, a convex block 153 is attached to the upper end of the actuator 15, and the upper surface of the convex block 153 has a shape including a convex spherical surface 153a that faces the concave spherical surface 162b. The concave spherical surface 162b and the convex spherical surface 153a are joined by an adhesive or the like.

[0016] In the above configuration, when the main screw 161 is screwed in, the slide member 162 having the sub-screw 162a descends at the pitch P1 together with the main screw 161. However, since the non-rotating sub-screw 162a ascends at the pitch P2, as a result, the slide member 162 descends at the pitch P = P1 - P2. Also, when the main screw 161 is rotated in the reverse direction, the slide member 162 ascends at the pitch P = P1 - P2. As described above, according to the height adjustment mechanism 16 of the present embodiment, compared with the conventional simple screwing mechanism, the vertical height position of the actuator 15 can be accurately adjusted. Also, according to this height adjustment mechanism 16, since the slide member 162 does not rotate, shear stress and bending stress hardly act on the actuator 15. Furthermore, according to the present embodiment, the differential screw mechanism which is the height adjustment mechanism 16 is attached to the main frame 11 of the dispenser body 1, and moreover, since the lower surface of the slide member 162 of this differential screw mechanism and the upper surface of the upper end portion of the actuator 15 are joined, the actuator 15 is supported by the differential screw mechanism which is the height adjustment mechanism 16. As a result, the self-weight of the actuator 15 hardly acts on the displacement amplification mechanism 14 (lever member 142), and the responsiveness of the displacement amplification mechanism 14 with respect to the high-speed driving of the actuator 15 (the followability of the rotational movement of the lever member 142) can be improved. Note that the actuator 15 is configured to include a piezo stack 151, and as a result, its self-weight hardly acts on the displacement amplification mechanism 14, so that a compressive force hardly acts on the piezo stack 151. However, in the present embodiment, a preloading member 152 is used to actively apply a compressive force. Thereby, the operating stability of the actuator 15 including the piezo stack 151 is improved. However, the preloading member can be omitted in the present invention.

[0017] Furthermore, in the present embodiment, since the lower surface of the slide member 162 includes a concave spherical surface 162b and the upper surface of the convex block 153, which is the upper end portion of the actuator 15, includes a convex spherical surface 153a that mates with the concave spherical surface 162b, when the vertical height position of the actuator 15 is adjusted by the height adjustment mechanism 16, the actuator 15 is automatically centered so as to stand upright in the vertical direction. That is, after the concave spherical surface 162b of the slide member 162 and the convex spherical surface 153a of the actuator 15 are mated, before joining, by conforming the concave spherical surface 162b and the convex spherical surface 153a, the actuator 15 is automatically centered so as to stand upright in the vertical direction. Thereafter, the concave spherical surface 162b and the convex spherical surface 153a are joined by an adhesive or the like. Thus, in the present embodiment, since the actuator 15 is automatically centered so as to stand upright in the vertical direction, the uprightness of the actuator 15 can be ensured, contributing to an improvement in the operation accuracy and an increase in the service life of the actuator 15. In the present embodiment, the lower surface of the slide member 162 includes the concave spherical surface 162b and the upper surface of the convex block 153, which is the upper end portion of the actuator 15, includes the convex spherical surface 153a that mates with the concave spherical surface 162b. However, the concave spherical surface and the convex spherical surface may be reversed, such that the lower surface of the slide member 162 includes the convex spherical surface and the upper surface of the upper end portion of the actuator 15 includes the concave spherical surface that mates with the convex spherical surface, and the same effect can be obtained with this configuration.

[0018] In addition, in the present embodiment, as the differential screw mechanism, a configuration in which the auxiliary screw 162a is screwed into the inside of the main screw 161 as described above is adopted. However, the configuration of the differential screw mechanism is not limited to this. For example, the main screw portion of the shaft in which the main screw and the auxiliary screw are integrated can be attached to the female screw portion (nut) 113 of the main frame 11, and a slide member can be attached to the auxiliary screw portion. In this configuration as well, the slide member is attached so as not to rotate. In any case, in the present invention, in the differential screw mechanism attached to the frame of the dispenser body, the lower surface of the slide member that slides in the vertical direction is joined to the upper surface of the upper end portion of the actuator. As a result, the vertical height position of the actuator can be accurately adjusted, and at this time, the effect that shear stress and bending stress hardly act on the actuator, and further, the effect that the responsiveness of the displacement amplification mechanism with respect to the high-speed driving of the actuator can be improved can be obtained.

[0019] Next, the operation of the dispenser X will be described. When the tip of the tappet 34 moves upward in the supply passage 33 in which the liquid material is introduced and filled through the liquid material introduction portion 312, the liquid material is supplied near the nozzle 32. At this time, an appropriate back pressure value is applied to the liquid material introduced into the liquid material introduction portion 312 according to the properties such as the viscosity of the liquid material. When the tip of the tappet 34 moves downward in the supply passage 33 in the direction approaching the nozzle 32, that is, when moving downward, the pressure of the liquid material near the nozzle 32 increases and the liquid material is discharged. After that, when the tip of the tappet 34 moves upward in the supply passage 33, the liquid material is supplied near the nozzle 32 again. Further, after that, when the tip of the tappet 34 moves downward in the supply passage 33, the liquid material is discharged from the nozzle 32. In this way, by the reciprocating movement of the tip of the tappet 34 in the vertical direction in the supply passage 33, the liquid material is intermittently discharged from the nozzle 32. The adjustment of the vertical height position of the actuator 15 is performed to adjust the distance between the tip of the tappet 34 and the tip (opening) of the nozzle 32.

Explanation of reference numerals

[0020] X Dispenser 1 Dispenser body 11 Main frame 111 Cover 112 Tappet mounting hole 113 Female screw part (nut) 12 Power supply terminal 13A Air introduction part 13B Air discharge part 14 Displacement amplification mechanism 141 Fulcrum member 142 Lever member 142a Fulcrum part 142b Acting point part 142c Force point part 143 Second biasing member 15 Actuator 151 Piezo stack 152 Preloading member 153 Upper end part of actuator (convex block) 153a Convex spherical surface 16 Height adjustment mechanism (differential screw mechanism) 161 Main screw 162 Slide member 162a Sub screw 162b Concave spherical surface 163 Guide pin 3 Nozzle block 31 Block body 311 Nozzle mounting part 312 Liquid material introduction part 32 Nozzle 321 Nozzle nut 33 Supply flow path 34 Tappet 341 Tappet holder 342 First biasing member

Claims

1. A dispenser comprising: a nozzle for ejecting a liquid material; a supply flow path for supplying the liquid material to the nozzle; a tappet having a tip portion that moves up and down in the supply flow path; a displacement magnifying mechanism for applying a displacement to the tappet; an actuator for applying a displacement to the displacement magnifying mechanism; and a height adjustment mechanism for adjusting a vertical height position of the actuator, The actuator includes a piezo stack in which piezo elements are stacked, The height adjustment mechanism comprises a differential screw mechanism attached to a frame of the dispenser body, and the lower surface of a slide member that slides vertically in the differential screw mechanism is joined to the upper surface of the upper end of the actuator.

2. The dispenser of claim 1 , wherein the actuator further comprises a preload member that applies a preload to the piezo stack.

3. 3. The dispenser according to claim 1 or 2, wherein the lower surface of the slide member comprises a concave or convex spherical surface, and the upper surface of the upper end of the actuator comprises a convex or concave spherical surface that mates with the concave or convex spherical surface.

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