Conveying device

Abstract

A conveyance device (10) is provided with: a vibration plate (20) that holds a product in a non-contact manner; a base (12) for supporting the vibration plate (20); and a vibrating element (40) that generates an ultrasonic holding force on the vibrating plate (20) by applying vibration to the vibrating plate (20), the vibrating plate (20) having: a peripheral portion (24) fixed to the base (12); and a central part (22) which is connected to the peripheral part (24) so as to be able to vibrate with respect to the peripheral part (24), and which amplifies the vibration applied from the vibration element (40).

Description

Conveying device Technical Field

[0001] This specification discloses a conveying device that uses ultrasound to hold an article in a non-contact manner. Background Technology

[0002] Conventional conveying devices that utilize ultrasound to hold articles in a non-contact manner are known. For example, Patent Document 1 discloses a holding device comprising: an ultrasonic transducer; a horn that amplifies and transmits the ultrasonic vibrations generated by the ultrasonic transducer; and a vibrating plate mounted at the end of the horn. This holding device holds the object in a non-contact manner through the ultrasonic compression effect generated on the surface of the vibrating plate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 5402542 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, such ultrasonic conveying devices typically require a relatively long horn in the axial direction. As a result, under current technology, it is necessary to increase the overall size of the conveying fixture.

[0008] Therefore, this specification discloses a conveying device that can be further miniaturized.

[0009] Technical means to solve the problem

[0010] The conveying device disclosed in this specification is characterized by comprising: a vibrating plate for holding an article in a non-contact manner; a base for supporting the vibrating plate; and a vibrating element for generating an ultrasonic holding force by applying vibration to the vibrating plate, the vibrating plate having: a peripheral portion fixed to the base; and a central portion connected to the peripheral portion in a manner capable of vibrating relative to the peripheral portion and amplifying the vibration applied from the vibrating element.

[0011] In this case, a groove or a gap extending through the vibrating plate in the thickness direction may be formed between the central portion and the peripheral portion. Alternatively, a gap extending through the vibrating plate in the thickness direction may be formed between the central portion and the peripheral portion, and the central portion and the peripheral portion may be connected by a bridge spanning the gap. Alternatively, the bridge may be symmetrically arranged when viewed from the center of the central portion.

[0012] Alternatively, the shape of the central portion may be substantially the same as the shape of the article.

[0013] Alternatively, the end face of the central portion may protrude further toward the direction of the article being held than the end face of the peripheral portion.

[0014] Alternatively, a space may exist between the base and the central portion.

[0015] Alternatively, the vibrating element may be fixed to the vibrating plate. In this case, the vibrating element may be fixed to the back of the peripheral portion. Alternatively, the vibrating elements may be symmetrically arranged when viewed from the center of the central portion. Alternatively, the vibrating element may be fixed to the vibrating plate by an adhesive of a thickness equal to the surface roughness of the vibrating plate.

[0016] Alternatively, the mass of the vibrating plate may be less than the mass of the base. Alternatively, the specific gravity of the vibrating plate may be less than the specific gravity of the base. Alternatively, the vibrating plate may be made of a material with a vibration Q-value greater than that of the base. In this case, the vibrating plate may be made of aluminum, titanium, or alloys thereof, and the base may be made of stainless steel, copper, or a copper alloy.

[0017] Alternatively, a suction hole for drawing the article may be formed in the central portion. In this case, a flexible tube may be included, which connects the suction hole to a suction source fluid. Alternatively, a plurality of airflow forming grooves connected to the suction hole may be formed on the end face of the central portion.

[0018] The effects of the invention

[0019] According to the technology disclosed in this specification, since the central part can vibrate relative to the peripheral part, the central part can vibrate appropriately even without a horn. As a result, the conveying device can be further miniaturized. Attached Figure Description

[0020] [Figure 1] is a bottom view of the conveying device.

[0021] [Figure 2] is a schematic cross-sectional view of the conveying device.

[0022] [Figure 3] is a diagram illustrating the principle of adsorption of the product.

[0023] [Figure 4] is a bottom view showing an example of another vibrating plate.

[0024] [Figure 5] is a bottom view showing an example of another vibrating plate.

[0025] [Figure 6] is a cross-sectional view showing an example of another vibrating plate.

[0026] [Figure 7] is a bottom view showing an example of another vibrating plate. Detailed Implementation

[0027] The structure of the conveying device 10 will now be described with reference to the accompanying drawings. Figure 1 is a bottom view of the conveying device 10. Figure 2 is a schematic AA cross-sectional view of the conveying device 10. Furthermore, in Figure 1, only the vibrating plate 20 is shaded.

[0028] The conveying device 10 is a device that uses ultrasound to hold articles in a non-contact manner. Hereinafter, an example of a conveying device 10 for holding a semiconductor chip as an article will be described. However, there is no particular limitation on the type of article to be held. Therefore, the conveying device 10 is not limited to semiconductor chips, and can also hold other articles such as precision mechanical parts or precision medical devices.

[0029] As shown in Figure 2, the conveying device 10 is generally divided into a base 12 and a vibrating plate 20. The base 12 is a generally block-shaped component fastened to the vibrating plate 20. The base 12 is quadrilateral when viewed from above, and fastening protrusions 14 protruding toward the vibrating plate 20 are formed at the four corners of the base 12. The fastening protrusions 14 are screwed and fastened to the fastening portion 34 of the vibrating plate 20, which will be described later. In other words, only the fastening protrusions 14 in the base 12 are in contact with the vibrating plate 20. Therefore, most of the base 12 is away from the vibrating plate 20, and there is a space between the base 12 and the vibrating plate 20.

[0030] This type of base 12 is connected to a moving mechanism (not shown). For example, in the case where the transport device 10 is adapted to a pick-up device for picking up semiconductor chips 100 from wafers, the transport device 10 is assembled to a collet for picking up semiconductor chips 100, and the base 12 is mechanically connected to a collet drive unit that moves the collet in the up, down, left, and right directions.

[0031] The vibrating plate 20 is a plate-shaped member fastened to the base 12. As shown in Figures 1 and 2, the vibrating plate 20 is roughly divided into a central portion 22 and a peripheral portion 24. The central portion 22 is actually the part that holds the product. A gap 30 extending through the thickness direction is formed around the central portion 22. As shown in Figure 3, the semiconductor chip 100, which is the product, is held with a space between it and the bottom surface of the central portion 22. The principle of this holding will be described later. Hereinafter, the surface of the vibrating plate 20 facing the product will be referred to as the "holding surface 37", and the opposite surface will be referred to as the "back surface 38".

[0032] The shape of the central portion 22 is approximately the same as that of the article being held. In this example, since a rectangular semiconductor chip 100 is being held, the central portion 22 is also rectangular. Furthermore, as shown in FIG2, the end face (i.e., the holding face 37) of the central portion 22 protrudes slightly downwards (i.e., towards the direction of the article being held) than the end face of the peripheral portion 24. This is to prevent the peripheral portion 24 from contacting the article when picking it up.

[0033] A suction hole 32 extending through the thickness direction is formed at the center of the central portion 22. A suction tube 46 containing flexible raw material is hermetically connected to the suction hole 32. The suction tube 46 fluidly connects a suction source 48, such as a vacuum pump, to the suction hole 32. A negative pressure is supplied to the suction hole 32 through the suction source 48 and the suction tube 46. Through this negative pressure, a force in the direction close to the central portion 22 acts on the product, which will be described later.

[0034] The central portion 22 is capable of vibrating relative to the peripheral portion 24. Specifically, as described above, a gap 30 extending through the thickness direction is formed between the central portion 22 and the peripheral portion 24. Furthermore, the central portion 22 is only partially connected to the peripheral portion 24 via connecting portions 26. In this example, the connecting portions 26 are four bridge portions 28 erected in the gap 30. The four bridge portions 28 are arranged symmetrically about the central portion 22. Specifically, two bridge portions 28 are provided on each long side of the central portion 22, for a total of four bridge portions 28. Therefore, the four corners of the central portion 22 become free ends not connected to the peripheral portion 24. When the vibrating plate 20 is subjected to vibration, the bridge portions 28 slightly flex, thereby causing the central portion 22 to vibrate relative to the peripheral portion 24. Furthermore, as shown in FIG2, in this example, the bridge portions 28 are made thinner than the peripheral portion 24 to facilitate flexing.

[0035] The peripheral portion 24 is a generally circular portion that completely surrounds the central portion 22. As shown in FIG1, the peripheral portion 24 has four fastening portions 34 protruding radially outward. Each fastening portion 34 has a fastening hole 36 for a fastening bolt to be inserted. As described above, the vibrating plate 20 is screwed into the base 12 in the fastening portions 34.

[0036] As shown in Figures 1 and 2, a vibrating element 40 is directly fixed to the back surface 38 of the vibrating plate 20. The vibrating element 40 is, for example, a unimorph-type vibrating element formed by bonding a thin piezoelectric element to a metal plate. In this example, the vibrating element 40 is fixed to the outer side of the peripheral portion 24, i.e., the central portion 22. Furthermore, the vibrating element 40 is arranged symmetrically about the central portion 22.

[0037] The vibrating element 40 is fixed to the vibrating plate 20, for example, by an adhesive. The adhesive is kept as thin as possible; for example, the adhesive thickness is set to a level that fills the surface roughness of the vibrating plate 20. The vibrating element 40 is electrically connected to an AC power supply 42. The vibrating element 40 generates ultrasonic vibrations based on the alternating voltage supplied from the AC power supply 42.

[0038] The vibrating plate 20 is selected in terms of its mass and material to ensure efficient vibration. Specifically, in this example, the size and material of the vibrating plate 20 are selected such that its mass is smaller than that of the base 12. Furthermore, the materials of both the vibrating plate 20 and the base 12 are selected such that the specific gravity of the vibrating plate 20 is less than that of the base 12, and that the vibration Q-value of the vibrating plate 20 is greater than that of the base 12. The vibration Q-value represents the attenuation characteristics of vibration; a larger Q-value indicates greater attenuation and longer vibration duration. When the resonant frequency at the resonance peak is set to ω0, and the frequencies to the left and right of the resonance peak where the vibration energy is half the resonance peak value are set to ω1 and ω2, the vibration Q-value can be calculated using the formula Q = ω0 / (ω2 - ω1). As a combination satisfying these conditions, the material of the vibrating plate 20 can be aluminum, titanium, or their alloys, and the material of the base 12 can be stainless steel, copper, or a copper alloy.

[0039] The controller 50 is physically a computer having a processor 52 and a memory 54. The controller 50 controls the driving of the suction source 48 and the AC power supply 42 to properly hold the article at the central part 22. This will be explained with reference to FIG3.

[0040] When an alternating voltage is applied to the vibrating element 40, the vibrating plate 20 undergoes ultrasonic vibration. In particular, the central portion 22, which is only partially connected to the base 12, undergoes greater ultrasonic vibration. When the semiconductor chip 100, which is a workpiece, is brought close to the central portion 22 while the ultrasonic vibration is occurring, an ultrasonic squeezing effect is generated between the holding surface 37 of the central portion 22 and the semiconductor chip 100. The ultrasonic squeezing effect is the effect of generating a higher pressure within the gap than outside due to the viscosity within the gap when one of two plates facing each other with a small gap is vibrated. When the ultrasonic squeezing effect occurs, an air film Sf is formed between the semiconductor chip 100 and the central portion 22, hindering contact between them, and a holding force is generated that holds the semiconductor chip 100 using the holding surface 37.

[0041] Here, the holding force generated by the ultrasonic squeezing effect (hereinafter referred to as "ultrasonic holding force") is generated in both the direction perpendicular to the holding surface 37 and the direction parallel to the holding surface 37 (i.e., the surface direction). That is, when the ultrasonic squeezing effect is generated, a force acts on the semiconductor chip 100 in a direction away from or above the holding surface 37. In addition, when the ultrasonic squeezing effect is generated, the semiconductor chip 100 intends to remain within the vibrating surface. Therefore, even if the semiconductor chip 100 is temporarily displaced in the surface direction by an external force, the semiconductor chip 100 moves along the surface direction with its entire body located within the vibrating surface and intends to return to the state facing the central portion 22.

[0042] Furthermore, the greater the ultrasonic energy (i.e., the greater the amplitude of ultrasonic vibration), the greater the thickness of the air film (hereinafter referred to as "ultrasonic extruded film Sf") generated by the ultrasonic extrusion effect, i.e., the greater the amount of the semiconductor chip 100 floating from the holding surface 37, Df. In addition, the greater the ultrasonic energy, the greater the ultrasonic holding force.

[0043] In this example, to assist in the ultrasonic holding force, a suction force based on negative pressure is also generated in the central portion 22. The controller 50 controls the driving of the suction source 48 and the AC power supply 42 while the semiconductor chip 100 is floating from the central portion 22, so as to balance the suction force, the ultrasonic holding force, and the gravity acting on the semiconductor chip 100.

[0044] Here, when the ultrasonic squeezing effect occurs, the semiconductor chip 100 is intended to be located within the vibrating surface. Therefore, if the shape of the central portion 22 is made approximately the same as that of the semiconductor chip 100, the semiconductor chip 100 will automatically move along the surface direction with its entire body located within the vibrating surface (i.e., in the region further inward than the shape of the central portion 22) due to the ultrasonic squeezing effect. In other words, by making the shape of the central portion 22 approximately the same as the shape of the semiconductor chip 100, self-alignment of the semiconductor chip 100 in the surface direction is possible.

[0045] However, conventionally, in order to effectively vibrate the central portion 22, a horn that amplifies the vibration is arranged between the vibrating element 40 and the central portion 22. However, when such a horn is installed, the conveying device 10 becomes larger. On the other hand, in this example, as described above, the central portion 22 is only partially connected to the peripheral portion 24. By adopting this structure, the central portion 22 vibrates easily. Furthermore, in this example, the material or mass of the central portion 22 and the base 12 is selected in a way that makes the central portion 22 vibrate more easily.

[0046] Therefore, even if the vibrating element 40 is directly fixed to the vibrating plate 20, the central part 22 can vibrate sufficiently. As a result, according to this example, since a horn is not required, the conveying device 10 can be greatly miniaturized.

[0047] Furthermore, if the suction tube 46 connected to the central portion 22 is a rigid body, the movement of the central portion 22 may be constrained by the suction tube 46. In this case, the central portion 22 cannot vibrate sufficiently, thus failing to obtain a proper ultrasonic compression effect. In this example, as described above, the suction tube 46 is a flexible tube that can be easily deformed. Therefore, the suction tube 46 does not hinder the vibration of the central portion 22. As a result, the central portion 22 can vibrate appropriately.

[0048] Furthermore, the structure described so far is one example, and other structures can be modified as long as they include the structure described in claim 1. For example, the shape of the central portion 22 can also be suitably modified. For example, when holding a square semiconductor chip 100, as shown in FIG4, the shape of the central portion 22 can also be square. In addition, the shape of the central portion 22 can also be a geometric shape such as a circle or a triangle, or a non-geometric shape such as a cloud shape.

[0049] Furthermore, the number or position of the bridge sections 28 can be appropriately changed. For example, as shown in Figure 4, one or more bridge sections can be provided on each of the four sides of the outer shape of the central section 22 forming the rectangle. In addition, the number of bridge sections 28 can be two or more than four.

[0050] Furthermore, the peripheral portion 24 can also be divided into two or more parts. For example, as shown in Figure 5, the peripheral portion 24 can be divided into two parts and arranged on the left and right sides of the central portion 22. In addition, the shape of the peripheral portion 24 can also be appropriately changed. For example, as shown in Figure 5, the peripheral portion 24 can also be approximately rectangular.

[0051] Furthermore, in the above description, a gap 30 extending along the thickness direction is formed around the central portion 22, and the central portion 22 is connected to the peripheral portion 24 via a bridge portion 28. However, if the central portion 22 can vibrate relative to the peripheral portion 24, in other words, if the connecting portion 26 can be easily flexed, it can also be in other forms. For example, as shown in FIG6, a dividing groove 60 can be formed around the central portion 22 instead of a gap 30. By forming the dividing groove 60, a thin-walled portion 62 is formed around the central portion 22. The thin-walled portion 62 functions as a connecting portion 26 connecting the central portion 22 and the peripheral portion 24. In addition, the thin-walled portion 62 is less rigid and more easily flexed compared to the periphery. As a result, by providing the thin-walled portion 62, the central portion 22 can vibrate relative to the peripheral portion 24.

[0052] Furthermore, as another embodiment, as shown in FIG7, a plurality of airflow forming grooves 64 connected to the suction hole 32 may be formed on the bottom surface of the central portion 22. Compared with the case where the airflow forming grooves 64 are not formed, the positioning accuracy of the semiconductor chip 100 in the planar direction is improved. It is speculated that the principle of achieving this effect is that by forming the airflow forming grooves 64, the airflow in the planar direction flowing between the semiconductor chip 100 and the bottom surface of the central portion 22 is accelerated and stabilized.

[0053] Alternatively, in another embodiment, the airflow forming groove 64 needless to say, the suction hole 32 may not be present. That is, the article may be held solely by ultrasonic holding force, without relying on suction holding force. Furthermore, in the description so far, the vibrating plate 20 and the base 12 have been described as separate components, but they may also be integrated. Moreover, the vibrating element 40 may be fixed to other locations. For example, the vibrating element 40 may be fixed to the side of the vibrating plate 20.

[0054] Explanation of icon numbers

[0055] 10: Conveying device

[0056] 12: Base

[0057] 14: Fastening protrusion

[0058] 20: Vibrating plate

[0059] 22: Central Department

[0060] 24: Surrounding Area

[0061] 26: Connecting parts

[0062] 28: Bridge section

[0063] 30: Gap

[0064] 32: Suction hole

[0065] 34: Fastening part

[0066] 36: Fastening hole

[0067] 37: Keep the surface

[0068] 38: Back

[0069] 40: Vibration element

[0070] 42: AC power supply

[0071] 46: Suction straw

[0072] 48: Suction Source

[0073] 50: Controller

[0074] 52: Processor

[0075] 54: Memory

[0076] 60: Dividing slots

[0077] 62: Thin-walled section

[0078] 64: Airflow Formation Groove

[0079] 100: Semiconductor chip

[0080] Sf: Ultrasonic extrusion film

Claims

1. A conveying device, characterized in that, include: A vibrating plate is used to hold the product in a non-contact manner. The base supports the vibrating plate; The vibrating plate also includes a vibrating element that generates an ultrasonic holding force by applying vibration to the vibrating plate. The vibrating plate has a peripheral portion fixed to the base and a central portion connected to the peripheral portion in a manner that enables it to vibrate relative to the peripheral portion and amplifies the vibration applied from the vibrating element.

2. The conveying device according to claim 1, characterized in that, A groove or a gap extending through the thickness direction of the vibrating plate is formed between the central portion and the peripheral portion.

3. The conveying device according to claim 2, characterized in that, A gap is formed between the central portion and the peripheral portion, extending through the vibrating plate in the thickness direction, and the central portion and the peripheral portion are connected by a bridge portion spanning the gap.

4. The conveying device according to claim 3, characterized in that, The bridge section is symmetrically arranged when viewed from the center of the central section.

5. The conveying device according to claim 1, characterized in that, The shape of the central portion is substantially the same as the shape of the article.

6. The conveying device according to claim 1, characterized in that, The end face of the central portion protrudes further toward the direction of the article being held than the end face of the peripheral portion.

7. The conveying device according to claim 1, characterized in that, There is a space between the base and the central portion.

8. The conveying device according to claim 1, characterized in that, The vibrating element is fixed to the vibrating plate.

9. The conveying device according to claim 8, characterized in that, The vibrating element is fixed to the back of the peripheral portion.

10. The conveying device according to claim 9, characterized in that, The vibrating elements are arranged symmetrically when viewed from the center of the central portion.

11. The conveying device according to any one of claims 8 to 10, characterized in that, The vibrating element is fixed to the vibrating plate by an adhesive of a thickness that fills the surface roughness of the vibrating plate.

12. The conveying device according to claim 1, characterized in that, The mass of the vibrating plate is less than the mass of the base.

13. The conveying device according to claim 1, characterized in that, The specific gravity of the vibrating plate is less than that of the base.

14. The conveying device according to claim 13, characterized in that, The vibrating plate is made of a material whose vibration Q value is greater than that of the base.

15. The conveying device according to claim 13 or 14, characterized in that, The vibrating plate is made of aluminum, titanium, or their alloys, and the base is made of stainless steel, copper, or copper alloys.

16. The conveying device according to claim 1, characterized in that, A suction hole for drawing the product is formed in the central part.

17. The conveying device according to claim 16, characterized in that, It includes a flexible tube that connects the suction port to the suction source fluid.

18. The conveying device according to claim 16 or 17, characterized in that, Multiple airflow forming grooves connected to the suction hole are formed on the end face of the central part.

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