Powder adjustment unit

Abstract

A powder adjustment unit (11) is provided with: a hollow squeegee (3); a first horn (10a) connected to one side of the squeegee (3); a second horn (10b) connected to the other side of the squeegee (3); a first vibrator (1) for exciting waves in the squeegee (3); and a second vibrator (2) for exciting waves in the squeegee (3). Both ends of the squeegee (3) are open ends. The first vibrator (1) is connected to the one side of the squeegee (3) via the first horn (10a), and the second vibrator (2) is connected to the other side of the squeegee (3) via the second horn (10b). The first vibrator (1) and the second vibrator (2) vibrate such that the waves excited by the first vibrator (1) and the waves excited by the second vibrator (2) are different in phase.

Description

Powder adjustment unit 【0001】 The present disclosure relates to a powder adjustment unit. 【0002】 In recent years, a dry coating method of directly coating powder has attracted attention. This dry coating method is evaluated as a method that can form a powder layer with high performance and low environmental impact compared to the wet coating method of dispersing powder in a solvent and coating. According to the dry coating method, (i) since no solvent is used, damage to the powder is less, and the high performance of the powder can be maintained, and (ii) there is no need to dry the solvent, the amount of energy consumption can be significantly reduced, and a powder layer can be efficiently formed. 【0003】 As a specific method of dry coating, a technique of coating powder on the surface of a substrate while transporting the substrate such as a metal foil by a transport device has been conventionally known. 【0004】 For example, Patent Document 1 discloses a technique of uniformly coating powder on the surface of a long metal foil. Specifically, after supplying powder to the surface of the metal foil, the powder is flattened by a squeegee that vibrates the powder, thereby uniformly adjusting the thickness of the powder. In the present disclosure, a mechanism that adjusts the amount of powder by leveling the powder supplied onto a substrate such as a metal foil and having a squeegee is called a powder adjustment unit. 【0005】 Japanese Patent Application Laid-Open No. 2021-178271 【0006】 However, in the powder layer formed by the dry coating method, in order to improve the quality of the powder layer, the uniformity of the basis weight may be required in some cases. 【0007】 Therefore, an object of the present disclosure is to provide a powder adjustment unit capable of forming a powder layer with reduced variation in basis weight. 【0008】To achieve the above objective, a powder adjustment unit according to one aspect of the present disclosure comprises a hollow squeegee, a first horn connected to one side of the squeegee, a second horn connected to the other side of the squeegee, a first vibrator for exciting the squeegee with waves, and a second vibrator for exciting the squeegee with waves, wherein both ends of the squeegee are open ends, the first vibrator is connected to the one side of the squeegee via the first horn, and the second vibrator is connected to the other side of the squeegee via the second horn, and the first vibrator and the second vibrator vibrate such that the phase of the wave excited by the first vibrator and the phase of the wave excited by the second vibrator are different. 【0009】 According to one aspect of the present disclosure, a powder preparation unit can be used to form a powder layer with suppressed variations in basis weight. 【0010】 Figure 1 shows an example of a powder coating apparatus. Figure 2A shows the vibration of the squeegee when viewed from the front in the direction of travel of the squeegee of the powder coating apparatus shown in Figure 1. Figure 2B shows the powder layer coated by the powder coating apparatus shown in Figure 1 when viewed from the front. Figure 3 is a perspective view showing a powder adjustment unit according to an embodiment. Figure 4 is a cross-sectional view showing a powder adjustment unit according to an embodiment. Figure 5 is a graph showing the relationship between squeegee position and amplitude according to an embodiment. 【0011】 (Background to obtaining one aspect of this disclosure) First, the background to obtaining one aspect of this disclosure will be explained with reference to Figures 1 to 2B. 【0012】 Figure 1 shows an example of a powder coating apparatus 30. Figure 2A shows the vibration of the squeegee 23 of the powder coating apparatus 30 shown in Figure 1 when viewed from the front in the direction of travel of the sheet 25. Figure 2B shows the powder layer 28 coated by the powder coating apparatus 30 shown in Figure 1 when viewed from the front. Figure 2A also schematically shows the vibration waveform when the squeegee 23 resonates (naturally vibrates) with a sinusoidal standing wave when viewed from the front. 【0013】As shown in Figure 1, the squeegee 23 vibrates at a high frequency near the ultrasonic band (for example, a frequency of 2 kHz to 300 kHz) by a vibration generator such as a transducer (not shown), and smooths the powder 24 supplied onto the sheet 25 to form a powder layer 28. In the powder coating apparatus 30, for example, as the sheet 25 moves in the direction indicated by the white arrow, the powder 24 passes through the gap between the sheet 25 and the squeegee 23, and the powder layer 28 is formed. At this time, the vibration of the squeegee 23 is transmitted to the powder 24, improving the fluidity of the powder 24 and achieving coating that suppresses powder blockage. 【0014】 Furthermore, as shown in Figure 2A, when the squeegee 23 is vibrated at a high frequency, the squeegee 23 vibrates in a sinusoidal standing wave due to resonance (natural vibration). As a result, a sinusoidal standing wave-like uneven structure is formed on the surface of the powder layer 28 that has passed through the gap between the sheet 25 and the squeegee 23, as shown in Figure 2B. Consequently, the variation in basis weight of the powder layer 28 becomes large. 【0015】 Based on the above, the inventors have noticed that when the squeegee 23 is vibrated to improve the fluidity of the powder 24 during the formation of the powder layer 28, a large variation in the basis weight of the powder layer 28 occurs due to the vibration of the squeegee 23, resulting in the formation of a low-quality powder layer 28. 【0016】 Therefore, this disclosure provides a powder adjustment unit, etc., that can form a powder layer 28 with suppressed variations in basis weight even when the squeegee 23 is vibrated. 【0017】 (Summary of this disclosure) An example of a powder preparation unit related to this disclosure is shown below. 【0018】A powder adjustment unit according to a first aspect of the present disclosure is a powder adjustment unit that adjusts the amount of powder supplied onto a substrate by leveling the powder, and comprises a hollow squeegee, a first horn connected to one side of the squeegee, a second horn connected to the other side of the squeegee, a first vibrator for exciting waves to the squeegee, and a second vibrator for exciting waves to the squeegee, wherein both ends of the squeegee are open ends, the first vibrator is connected to one side of the squeegee via the first horn, and the second vibrator is connected to the other side of the squeegee via the second horn, and the first vibrator and the second vibrator vibrate such that the phase of the wave excited by the first vibrator and the phase of the wave excited by the second vibrator are different. As a result, the squeegee vibrates with traveling waves from one side to the other, or with traveling waves from the other side to the one side. 【0019】 This makes it less likely for antinodes and nodes of a sinusoidal standing wave to occur on the squeegee. Therefore, the powder layer formed by leveling the powder is less likely to have irregularities caused by the vibration of the squeegee, and a powder layer with suppressed variations in basis weight can be formed. 【0020】 The embodiments of this disclosure will be described below with reference to the drawings. 【0021】 The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps (processes), and the order of steps (processes) shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components. 【0022】Furthermore, in the following embodiments, expressions such as longitudinal direction, near XX, approximately equal, and elongated are used. For example, longitudinal direction, near XX, approximately equal, and elongated not only mean perfectly longitudinal, perfectly XX, equal, and perfectly elongated, but also substantially longitudinal, substantially XX, substantially equal, and substantially elongated, that is, including an error of, for example, a few percent. Also, longitudinal direction, near XX, approximately equal, and elongated mean longitudinal, XX, equal, and elongated to the extent that the effects of this disclosure can be achieved. The same applies to other expressions using "longitudinal direction," "approximately," and "shape." XX is the numerical value shown in this embodiment. 【0023】 Furthermore, each figure is a schematic diagram that has been appropriately emphasized, omitted, or had its proportions adjusted to illustrate this disclosure, and is not necessarily a strict representation; it may differ from the actual shape, positional relationships, and proportions. In each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified. 【0024】 (Embodiment) [Powder preparation unit 11] First, the powder preparation unit 11 according to this embodiment will be described with reference to Figures 3 and 4. 【0025】 Figure 3 is a perspective view showing the powder preparation unit 11 according to this embodiment. Figure 4 is a cross-sectional view showing the powder preparation unit 11 according to this embodiment. 【0026】 As shown in Figures 3 and 4, in the powder adjustment unit 11, a squeegee 3 is connected to one end of the squeegee 3 via a first horn (joint) 10a, and a first transducer 1 for exciting waves is connected to that end. Furthermore, in the powder adjustment unit 11, a second transducer 2 for exciting waves is connected to the other end of the squeegee 3 via a second horn (joint) 10b. In this embodiment, a case in which a standing wave is used as an example of the wave to be excited is illustrated. However, the wave to be excited is not limited to a standing wave. 【0027】Furthermore, the powder adjustment unit 11 is equipped with a function generator 9. The sine wave signal generated by the function generator 9 is amplified by the first amplifier 6, and the sine wave represented by this amplified sine wave signal vibrates the first oscillator 1. 【0028】 On the other hand, the sine wave signal of the same frequency (same wavelength) but with a phase shift generated by the function generator 9 is amplified by the second amplifier 7, and the sine wave represented by this amplified sine wave signal causes the second oscillator 2 to vibrate. In other words, the first oscillator 1 and the second oscillator 2 vibrate with sine waves of the same frequency (same wavelength) but with a phase shift. 【0029】 The first oscillator 1 vibrates the squeegee 3 via the first horn 10a, and the second oscillator 2 also vibrates the squeegee 3 via the second horn 10b. In other words, by making the phases of the vibrations of the first oscillator 1 and the second oscillator 2 different, the squeegee 3 vibrates either due to a traveling wave traveling from one side to the other, or due to a traveling wave traveling from the other side to the first side. In Figure 4, the arrows illustrate the case where the squeegee 3 vibrates due to a traveling wave traveling from one side to the other. 【0030】 As a method for sending sinusoidal signals of the same wavelength (same frequency) and the same amplitude, with phase shifts between the vibrations of the first oscillator 1 and the second oscillator 2, a method using a function generator 9 equipped with two output terminals and having the function of shifting the phases has been described, but this method is not the only one. 【0031】 The powder adjustment unit 11 adjusts the amount of powder 4 on the sheet 5 by leveling the powder 4 supplied onto the sheet 5 using the squeegee 3, thereby forming a powder layer 8. 【0032】 In this embodiment, the squeegee 3 is a long, cylindrical shape, the first transducer 1 is connected to one end of the squeegee 3 in the longitudinal direction via a first horn 10a, and the second transducer 2 is connected to the other end of the squeegee 3 in the longitudinal direction via a second horn 10b. Both ends of the squeegee 3 in this embodiment are open. 【0033】The squeegee 3 is a hollow, pipe-shaped structure, but it is preferable to make the squeegee 3 a cylindrical pipe shape. By making the squeegee 3 cylindrical, the amplitude of the traveling wave can be increased, and the alignment effect on the powder 4 can be increased. When the squeegee is cylindrical, the rigidity of the squeegee is higher and it is less prone to deformation compared to when the squeegee 3 is cylindrical. Also, a cylindrical squeegee is heavier than a cylindrical squeegee, making it more difficult to vibrate. Therefore, in this embodiment, by making the squeegee 3 cylindrical, the wall thickness of the squeegee 3 can be reduced, which reduces the rigidity and weight of the squeegee 3, making it easier to vibrate. The thinner the squeegee 3, the better; it is sufficient as long as the mechanical strength of the squeegee 3 is maintained, for example, 0.5 mm or more is sufficient. Preferably, if the squeegee 3 has a thickness of 1 mm to 5 mm, it is expected that both the strength and ease of vibration of the squeegee 3 can be achieved. 【0034】 Furthermore, if the squeegee has a hollow structure, the same effect as when the squeegee 3 is cylindrical can be obtained. In particular, the cylindrical shape of the squeegee 3 is more preferable because the direction of the ultrasonic waves applied to the powder 4 spreads evenly in all directions toward the perpendicular direction perpendicular to the longitudinal direction of the squeegee 3. 【0035】 Furthermore, in this specification, "long length" means that the length in one direction is at least twice the length in any direction perpendicular to that direction. 【0036】 The squeegee 3 is vibrated by the first oscillator 1 and the second oscillator 2 by traveling waves traveling from one end to the other, and by traveling waves traveling from the other end to the first end. Therefore, the position where the amplitude is maximum on the squeegee 3 moves over time. As shown in Figure 4, the traveling wave propagates along the longitudinal direction of the squeegee 3. 【0037】The ends of the squeegee 3 are open ends. That is, the first horn 10a is fixed to the squeegee 3 further back than one end of the squeegee 3, and the second horn 10b is an open end fixed to the squeegee 3 further back than the other end of the squeegee 3. In other words, one end and the other end of the squeegee 3 are free ends that are not fixed to the first horn 10a and the second horn 10b. 【0038】 In this embodiment, a first transducer 1 is connected to one side of the squeegee 3 via a first horn 10a, and a second transducer 2 is connected to the other side of the squeegee 3 via a second horn 10b. The first horn 10a and the second horn 10b are connected to both sides of the squeegee 3 by being inserted from the inside of the cylinder of the squeegee 3. Specifically, the first horn 10a, inserted through an opening 3a formed on one side of the squeegee 3, is connected inside the squeegee 3 on that side, and the second horn 10b, inserted through an opening 3b formed on the other side of the squeegee 3, is connected inside the squeegee 3 on the other side. 【0039】 The first horn 10a is connected to the first oscillator 1, and the second horn 10b is connected to the second oscillator 2. 【0040】 The roles of the first horn 10a and the second horn 10b are to amplify the amplitudes of the first oscillator 1 and the second oscillator 2, and to act as couplings connecting the first oscillator 1 and the second oscillator 2 to the squeegee 3. 【0041】 The "end" of the squeegee 3 to which the first horn 10a and the second horn 10b are connected does not mean the tip (one end and the other end) of the squeegee 3 in a certain direction, but rather the portion within a predetermined range from the tip of the squeegee 3 in a certain direction. In other words, the end of the squeegee 3 is a general term that includes a portion having a predetermined length along the longitudinal direction from one end of the squeegee 3 and a portion having a predetermined length along the longitudinal direction from the other end of the squeegee 3. 【0042】 The tip of the squeegee 3 refers to one end of the squeegee 3 and the other end of the squeegee 3. 【0043】Next, we will explain why it is good for both ends of the squeegee 3 to be open ends. 【0044】 When the first oscillator 1 is connected to the squeegee 3 via the first horn 10a connected to one side of the squeegee 3, and the second oscillator 2 is connected to the squeegee 3 via the second horn 10b connected to the other side of the squeegee 3, a wide variety of vibration modes can be generated. For example, there are three vibration modes: (1) integrated vibration of the first oscillator 1 and second oscillator 2 and the first horn 10a and second horn 10b, (2) vibration of the squeegee 3, and (3) integrated vibration of the entire system consisting of the first oscillator 1 and second oscillator 2, the first horn 10a and second horn 10b, and the squeegee 3. The existence of three such vibration modes makes the system complex. While traveling waves are generated in simulations, it is difficult to generate traveling waves in experiments due to errors in manufacturing precision and other factors. 【0045】 Therefore, by making both ends of the squeegee 3 open ends, the vibrations of the first oscillator 1 and the second oscillator 2 and the first horn 10a and the second horn 10b are separated from the vibrations of the squeegee 3, thus simplifying the vibration modes. For this reason, a vibration mode is created in which the squeegee 3 vibrates on its own. As a result, in this embodiment, traveling waves can be easily generated even in experiments. 【0046】 It is preferable that the squeegee 3 is connected to the first horn 10a and the second horn 10b in a range of 1 / 3 to 2 / 3 of the wavelength excited at both ends of the squeegee 3. Specifically, it is preferable that one side of the squeegee 3 is connected to the first horn 10a in a range where the wavelength from one end of the squeegee 3 is 1 / 3 or more of the wavelength of the wave excited by the first oscillator 1, and 2 / 3 or less of the wavelength of the wave excited by the first oscillator 1. It is also preferable that the other side of the squeegee 3 is connected to the second horn 10b in a range where the wavelength from the other end of the squeegee 3 is 1 / 3 or more of the wavelength of the wave excited by the second oscillator 2, and 2 / 3 or less of the wavelength of the wave excited by the second oscillator 2. 【0047】For example, when a stainless steel squeegee 3 is vibrated at 39 kHz, the wavelength of the excited ultrasonic wave is approximately 90 mm. In this case, if the connection points between the first horn 10a and the squeegee 3, and the connection points between the second horn 10b and the squeegee 3 are set to 32 mm (1 / 3 wavelength) to 66 mm (2 / 3 wavelength) from the tip of the squeegee 3, a traveling wave is easily generated and the amplitude of the squeegee becomes large. In particular, the amplitude is maximized and preferable when each of these connection points is set to approximately 49 mm (about 1 / 4 wavelength) from the tip of the squeegee 3. 【0048】 The first horn 10a has a first connecting portion 10a1 connected to one side of the squeegee 3. The second horn 10b has a second connecting portion 10b1 connected to the other side of the squeegee 3. 【0049】 The width of the first connecting portion 10a1 connected to the squeegee 3 (thickness in the direction parallel to the longitudinal direction of the squeegee 3) and the width of the second connecting portion 10b1 connected to the squeegee 3 (thickness in the direction parallel to the longitudinal direction of the squeegee 3) are preferably 1 / 30 to 1 / 9 of the wavelength of the ultrasonic waves excited by the squeegee 3. Specifically, the length of the portion where the squeegee 3 is connected to the first connecting portion 10a1 and the length of the portion where the squeegee 3 is connected to the second connecting portion 10b1 are preferably 1 / 30 to 1 / 9 of the wavelength of the waves excited by the first transducer 1 and the second transducer 2. 【0050】 For example, when a stainless steel squeegee 3 is vibrated at 39 kHz, the wavelength of the excited ultrasonic wave is approximately 90 mm. In this case, if the width of the first connecting portion 10a1 and the width of the second connecting portion 10b1 connected to the squeegee 3 are set to 3 mm (1 / 30 wavelength) to 10 mm (1 / 9 wavelength), a traveling wave is more likely to be generated, and the amplitude of the squeegee 3 will increase. In particular, the amplitude is maximized and preferable when the length of the portion of the first connecting portion 10a1 and the second connecting portion 10b1 that connects to the squeegee 3 (the contact portion) is 6 mm (approximately 1 / 15 wavelength). 【0051】The first horn 10a has a diameter that changes near the center of its length, with the diameter on the first oscillator 1 side being equal to that of the first oscillator 1, and the diameter changing near the center of the first horn 10a. Similarly, the second horn 10b has a diameter that changes near the center of its length, with the diameter on the second oscillator 2 side being equal to that of the second oscillator 2, and the diameter changing near the center of the second horn 10b. 【0052】 Specifically, the first horn 10a further has a first main body portion 10a2 connected to the first connecting portion 10a1 on the side opposite to the squeegee 3. The second horn 10b further has a second main body portion 10b2 connected to the second connecting portion 10b1 on the side opposite to the squeegee. The outer diameter of the first main body portion 10a2 is approximately equal to the outer diameter of the first transducer 1, and the outer diameter of the second main body portion 10b2 is approximately equal to the outer diameter of the second transducer 2. 【0053】 The first main body 10a2 is a cylindrical body that extends along the longitudinal direction of the squeegee 3. The first main body 10a2 is inserted into the opening 3a on one side of the squeegee 3. The first main body 10a2 is connected to the first transducer 1 and has a first large-diameter portion 100a1 that extends along the longitudinal direction of the squeegee 3, and a first small-diameter portion 100a2 that is positioned between the first transducer 1 and the first large-diameter portion 100a1 and extends along the longitudinal direction of the squeegee 3. The total length of the first large-diameter portion 100a1 (length in the longitudinal direction of the squeegee 3) and the total length of the first small-diameter portion 100a2 (length in the longitudinal direction of the squeegee 3) are approximately equal. The first transducer 1 is connected to one end of the first large-diameter portion 100a1. The outer diameter of the first large-diameter portion 100a1 is approximately equal to the outer diameter of the first transducer 1. A first small-diameter portion 100a2 is connected to the other end of the first large-diameter portion 100a1. The first small-diameter portion 100a2 is cylindrical in shape. A first connecting portion 10a1 is formed at the tip of the first small-diameter portion 100a2. The first connecting portion 10a1 is flange-shaped and extends radially perpendicular to the first small-diameter portion 100a2 which extends along the longitudinal direction of the squeegee 3. The first connecting portion 10a1 extends radially from the first small-diameter portion 100a2 and is connected to the inner circumferential surface of the squeegee 3. The outer diameter of the first connecting portion 10a1 is larger than the outer diameter of the first large-diameter portion 100a1. 【0054】The second main body 10b2 is a cylindrical body that extends along the longitudinal direction of the squeegee 3. The second main body 10b2 is inserted into the opening 3b on the other side of the squeegee 3. The second main body 10b2 is connected to the second transducer 2 and has a second large-diameter portion 100b1 that extends along the longitudinal direction of the squeegee 3, and a second small-diameter portion 100b2 that is positioned between the second transducer 2 and the second large-diameter portion 100b1 and extends along the longitudinal direction of the squeegee 3. The total length of the second large-diameter portion 100b1 (length in the longitudinal direction of the squeegee 3) and the total length of the second small-diameter portion 100b2 (length in the longitudinal direction of the squeegee 3) are approximately equal. The second transducer 2 is connected to one end of the second large-diameter portion 100b1. The outer diameter of the second large-diameter portion 100b1 is approximately equal to the outer diameter of the second transducer 2. A second small-diameter portion 100b2 is connected to the other end of the second large-diameter portion 100b1. The second small-diameter portion 100b2 is cylindrical in shape. A second connecting portion 10b1 is formed at the tip of the second small-diameter portion 100b2. The second connecting portion 10b1 is flange-shaped and extends radially perpendicular to the second small-diameter portion 100b2, which extends along the longitudinal direction of the squeegee 3. The second connecting portion 10b1 extends radially from the second small-diameter portion 100b2 and is connected to the inner circumferential surface of the squeegee 3. The outer diameter of the second connecting portion 10b1 is larger than the outer diameter of the second large-diameter portion 100b1. 【0055】 The outer diameter of the first small-diameter portion 100a2 is preferably 7 / 15 or more and 4 / 5 or less of the outer diameter of the first main body portion 10a2. Furthermore, the outer diameter of the second small-diameter portion 100b2 is preferably 7 / 15 or more and 4 / 5 or less of the outer diameter of the second main body portion 10b2. 【0056】 The first horn 10a and the first transducer 1 are connected in contact, and the second horn 10b and the second transducer 2 are also connected in contact. However, vibrations are most easily transmitted when the diameters of the first horn 10a and the first transducer 1 are the same, and the diameters of the second horn 10b and the second transducer 2 are the same. 【0057】The first horn 10a and the second horn 10b have the role of amplifying vibrations. This is achieved by employing a structure in which the diameters of the first small-diameter section 100a2 and the second small-diameter section 100b2, which are further away from the first vibrator 1 and the second vibrator 2, become smaller. As a result, the weight of the first small-diameter section 100a2 and the second small-diameter section 100b2 is lighter than that of the first large-diameter section 100a1 and the second large-diameter section 100b1, so the amplitude is larger in the first small-diameter section 100a2 and the second small-diameter section 100b2 compared to the first large-diameter section 100a1 and the second large-diameter section 100b1. For example, when the diameter of the first oscillator 1 side of the first horn 10a and the second oscillator 2 side of the second horn 10b is 30 mm, when the diameter on the opposite side is 14 mm (7 / 15 of the diameter) to 24 mm (4 / 5 of the diameter), traveling waves are more likely to be generated and the amplitude of the squeegee 3 becomes larger. In particular, when the diameter of the first oscillator 1 side of the first horn 10a and the second oscillator 2 side of the second horn 10b is around 20 mm (2 / 3 of the diameter), traveling waves are most likely to be generated, which is preferable. 【0058】 The area where the diameter changes is preferably near the center of the first horn 10a and the second horn 10b. Since the change in stress is greatest in this area, the stress at which the effect of weight reduction is considered to be greatest is given by F = m × a. "m" is the weight of the first small-diameter section 100a2 and the second small-diameter section 100b2. "a" is the acceleration of the vibrating first small-diameter section 100a2 and the second small-diameter section 100b2. Since the stress "F" is greatest near the center of the first horn 10a and the second small-diameter section 10b, this area is utilized. At this time, if the weight "m" of the vibrating part (first small-diameter section 100a2 and second small-diameter section 100b2) is reduced, the acceleration "a" of the first small-diameter section 100a2 and the second small-diameter section 100b2 will increase, meaning that the effect of increasing the amplitude of vibration will be greater. 【0059】 Next, a method for aligning the powder 4 using a squeegee 3 will be described. 【0060】When forming the powder layer 8, the longitudinal direction of the squeegee 3 is, for example, in a top view of the sheet 5, a direction that intersects (specifically, is perpendicular to) the relative direction of travel of the squeegee 3 with respect to the sheet 5. In other words, in the squeegee 3, the direction of travel of the traveling wave intersects (specifically, is perpendicular to) the relative direction of travel of the squeegee 3 with respect to the sheet 5. 【0061】 First, powder 4 is supplied onto a sheet 5, which is a thin, flake-shaped component. Then, by moving the powder adjustment unit 11, the film thickness and packing density of the powder 4 are adjusted using a squeegee 3, forming a powder layer 8 with a desired powder amount (hereinafter referred to as basis weight) while minimizing variations in basis weight. In this embodiment, the sheet 5 may be referred to as the base material. 【0062】 Here, basis weight refers to the amount of powder per unit area expressed in weight, and the unit of basis weight is, for example, g / cm². ２ This is shown. 【0063】 In forming the powder layer 8, it is sufficient that the squeegee 3 and the powder 4 move relative to each other, and the powder adjustment unit 11 may be fixed while the sheet 5 and mask are moved. Alternatively, the powder adjustment unit 11, as well as the sheet 5 and mask, may be moved during the formation of the powder layer 8. Furthermore, there are no particular limitations on the means of moving these components; they may be moved automatically using a drive device or manually. 【0064】 In forming the powder layer 8, a predetermined gap is formed between the squeegee 3 and the sheet 5. The powder 4 supplied onto the sheet 5 passes through this gap. As the powder 4 passes through the gap, the squeegee 3 adjusts the film thickness and packing density of the powder 4 supplied to the surface of the sheet 5, reducing variations in the basis weight of the powder layer 8. 【0065】 In this embodiment, the sheet 5 is, for example, a current collector containing metal foil. The material and shape of the sheet 5 to which the powder 4 is supplied are not particularly limited. 【0066】The powder 4 can be any powdery substance. In other words, the raw materials of the powder 4, the composition of the powder 4, and the particle shape of the powder 4 are not particularly limited. In this embodiment, the powder 4 is a group of particles containing at least one of the active material and the solid electrolyte. 【0067】 The particle size (D50) of the powder 4 is, for example, 0.005 μm or more and 30 μm or less. When the particle size of the powder 4 decreases, the fluidity of the powder 4 tends to decrease, but the vibration of the squeegee 3 promotes the fluidity of the powder 4. Therefore, the accumulation and aggregation of the powder 4 are suppressed, and a powder layer 8 with little variation in basis weight can be formed. Here, the particle size (D50) is the volume-based median diameter calculated from the measured particle size distribution using laser diffraction / scattering methods, etc. This particle size (D50) can be measured using a commercially available laser analysis / scattering particle size distribution analyzer. 【0068】 Furthermore, powder 4 may contain only one type of powder, or it may contain two or more types of powder. 【0069】 Next, we will describe the details of the squeegee 3, the first oscillator 1 and the second oscillator 2, and the first horn 10a and the second horn 10b. 【0070】 [Squeegee 3, first oscillator 1 and second oscillator 2, first horn 10a and second horn 10b] The squeegee 3 vibrates via the first oscillator 1 through the first horn 10a and the second oscillator 2 through the second horn 10b. Therefore, unlike when the squeegee 3 vibrates with a sinusoidal standing wave, no nodes or antinodes are generated when the squeegee 3 vibrates. In other words, the squeegee 3 generates positions where the amplitude is maximum and minimum. Therefore, even when the squeegee 3 vibrates, no variation in basis weight caused by nodes and antinodes occurs, and a powder layer 8 with little variation in basis weight in the coating width direction can be formed. In this specification, the coating width direction of the powder layer 8 may be simply referred to as the "width direction". 【0071】 Next, we will describe the details of the generation of traveling waves in squeegee 3. 【0072】As described above, a first oscillator 1 is positioned at one end of the squeegee 3 and connected to the squeegee 3 via a first horn 10a. A second oscillator 2 is positioned at the other end of the squeegee 3 and connected to the squeegee 3 via a second horn 10b. The first oscillator 1 and the second oscillator 2 are excitation oscillators that provide an excitation force to vibrate the squeegee 3 with standing waves of different phases. Examples of excitation oscillators include Langevin oscillators (BLTs). 【0073】 The sine wave signal generated by the function generator 9 is amplified by the first amplifier 6, causing the first oscillator 1 to vibrate. In other words, the function generator 9 vibrates the first oscillator 1 with a sine wave. 【0074】 On the other hand, a sine wave of the same frequency (same wavelength) but with a phase shift is amplified by the second amplifier 7 and vibrates the second oscillator 2. In other words, the function generator 9 vibrates the second oscillator 2 with a sine wave that is phase-shifted relative to the sine wave that vibrates the first oscillator 1. To put it another way, the function generator 9 vibrates the first oscillator 1 and the second oscillator 2 with signals that are sine waves of the same frequency (wavelength) but are phase-shifted relative to each other. As a result, a traveling wave is generated in the squeegee 3. Specifically, as the first oscillator 1 vibrates the squeegee 3 with a sine wave, and the second oscillator 2 vibrates the squeegee 3 with a phase-shifted sine wave, the squeegee 3 vibrates with a traveling wave traveling from one end to the other, or from the other end to the first end. 【0075】 The length of squeegee 3 is set to a length that is shifted from n / 2 times the wavelength of the excited wave. In other words, the total length of squeegee 3 is a length that is shifted from n times half a wavelength of the sine wave excited on squeegee 3 by a length less than half a wavelength. n is a natural number greater than or equal to 1. Note that if the total length of the squeegee is equal to n times half a wavelength, it is thought that even if the phase is shifted, a sinusoidal standing wave will be excited on the squeegee and no traveling wave will be generated. 【0076】Next, a phase difference is given to the sine wave generated by the squeegee 3 by a length shifted from n times half the wavelength of the sine wave. The phase difference is the phase difference between the wave excited by the first oscillator 1 and the wave excited by the second oscillator 2, and is the length of the shift. For example, if the phase difference is "Φ", the length of the shift is "L", and the wavelength is "λ", then the phase difference "Φ" is given by equation (1). 【0077】 【0078】 For example, if "L" is (1 / 4)λ, then "Φ" will be π / 2. 【0079】 In this state, a traveling wave is generated in squeegee 3 from the first oscillator 1 to the second oscillator 2, and a sinusoidal standing wave is not generated. This is because no sinusoidal reflection occurs in squeegee 3, so a sinusoidal standing wave is not generated in squeegee 3, and a traveling wave is generated in squeegee 3. This is because a sinusoidal standing wave is generated by the superposition of a traveling wave and a reflected wave. 【0080】 Furthermore, if a phase difference of "-Φ" is set, a traveling wave is generated from the second oscillator 2 to the first oscillator 1. 【0081】 Specifically, when a stainless steel squeegee 3 is excited at a frequency of 39 kHz, the wavelength becomes 90 mm. Theoretically, it is preferable that the length of the squeegee 3 be approximately 8 times half a wavelength + 1 / 4 wavelength = 383 mm. At this time, the first oscillator 1 and the second oscillator 2 impart vibrations with a phase difference of π / 2 (90°) to the squeegee 3. 【0082】 Note that this is an ideal setting, and it is preferable to adjust the phase difference so that a traveling wave is generated according to the actual vibration state. 【0083】 Next, we will explain traveling waves using Figure 5. 【0084】Figure 5 is a graph showing the relationship between squeegee position and amplitude. Squeegee position refers to the displacement of squeegee 3 in the axial direction. Amplitude is the measured value of the amplitude of the vibrating squeegee 3. The measurement is performed using a laser Doppler vibrometer to measure the amplitude of squeegee 3. Amplitude represents the maximum value of the amplitude at each point on squeegee 3. The proportion of traveling waves is expressed as the standing wave ratio. The measured amplitude contains some standing wave components, resulting in a state where antinodes and nodes are repeated. If the part with the maximum value of the amplitude (antinode) is A, and the part with the minimum value next to it (node) is B, then the standing wave ratio can be expressed as A / B. It is preferable when the standing wave ratio is less than 1.4, as this indicates that the traveling wave component accounts for a large portion of the amplitude. When the standing wave ratio is less than 1.4, the amplitude difference becomes smaller, allowing for precise adjustment of the amount of powder in the axial direction (coating width direction) of squeegee 3. On the other hand, when the standing wave component is high, the amplitude difference between the maximum value (antinode) and the minimum value (node) of the standing wave becomes large, indicating that a large amount of the standing wave component is present. In this case, because the amplitude difference is large, the variation in the amount of powder in the axial direction (coating width direction) of the squeegee 3 becomes large. 【0085】 The squeegee 3 uses the vibration of a traveling wave to level the powder 4, thereby suppressing variations in the basis weight in the width direction of the powder layer 8 caused by the antinodes and nodes of a standing wave. In other words, by using the powder leveling unit 11, it is possible to form a powder layer 8 with less variation in basis weight in the width direction. Here, the width direction of the powder layer 8 is the direction perpendicular to the thickness direction of the powder layer 8 and the direction in which the squeegee 3 moves relative to the powder 4. 【0086】 The squeegee 3 is made of, for example, a metallic material. By using a metallic material for the squeegee 3, the attenuation of high-frequency vibrations propagating through the squeegee 3 can be suppressed. This is because short-wavelength high-frequency vibrations are easily attenuated, but metallic materials have the property of easily transmitting vibrations, thus suppressing attenuation. As a result, the amplitude of the sine wave generated from the first oscillator 1 and the amplitude of the sine wave generated from the second oscillator 2 can be made equal, making it easier for traveling waves to be generated in the squeegee 3. 【0087】Therefore, the variation in basis weight in the width direction of the powder layer 8 is reduced. The squeegee 3 may also contain materials other than metal. For example, the squeegee 3 may be a composite member made of resin material and metal material, with the portion through which the traveling wave propagates being made of metal material. Alternatively, the squeegee 3 may be made of ceramic material. 【0088】 Examples of metallic materials used include stainless steel, titanium, aluminum, copper, iron, and nickel. From the viewpoint of corrosion resistance, stainless steel or titanium may be used among these metallic materials. Furthermore, when titanium is used as the metallic material, titanium has a lower specific gravity than stainless steel, so titanium is more susceptible to vibration at high frequencies than stainless steel. 【0089】 Each of the first oscillator 1 and the second oscillator 2 includes, for example, a plurality of piezoelectric elements and electrodes provided on the end faces of each of the plurality of piezoelectric elements. In the first oscillator 1 and the second oscillator 2, each of the plurality of piezoelectric elements is sandwiched between a plurality of electrodes. Therefore, each of the first oscillator 1 and the second oscillator 2 has a sandwich structure of piezoelectric elements and electrodes. The number of piezoelectric elements included in each of the first oscillator 1 and the second oscillator 2 is an even number, such as two, four, or six. The electrodes are thin metal plates, such as copper and phosphor bronze. 【0090】 The first oscillator 1 and the second oscillator 2 are, for example, directly attached to the squeegee 3. The first oscillator 1 and the second oscillator 2 are positioned so as to be separated by a distance greater than or equal to the width of the powder layer 8 to be formed. 【0091】 Examples of piezoelectric materials include lead zirconate titanate (PbTiO) ３ -PbZrO ３ (System, commonly known as PZT) and barium titanate (BaTiO) ３ Piezoelectric ceramics such as ), as well as quartz and LiNbO ３ Examples include piezoelectric single crystals. When the piezoelectric material is a piezoelectric ceramic such as PZT, the thickness of each sheet is, for example, 2 mm to 5 mm. 【0092】Furthermore, the first oscillator 1 and the second oscillator 2 may each be a Langevin-type oscillator with a sandwich structure in which a piezoelectric body is sandwiched between a metal front plate and a metal backing plate, and the total length of the oscillator is half a wavelength. In this case, even if the Langevin-type oscillator is connected to the squeegee 3, it may be connected via the first horn 10a and the second horn 10b. Specifically, the Langevin-type oscillator has a structure in which a front plate and a backing plate, which are placed on both sides of a piezoelectric body such as a PZT, are fastened together with bolts. The front plate and the backing plate are made of duralumin, for example. The bolts are made of steel or titanium alloy, for example. 【0093】 The first horn 10a and the second horn 10b are each made of, for example, duralumin. The first horn 10a and the second horn 10b made of duralumin are preferred because they are lightweight, easily vibrate, and have a predetermined strength. 【0094】 The method for connecting the first horn 10a and the first transducer 1, and the method for connecting the second horn 10b and the second transducer 2, may involve forming screw holes at the respective ends of the first horn 10a and the second horn 10b, forming screw holes at the respective front plates of the first transducer 1 and the second transducer 2, connecting the end of the first horn 10a to the front plate of the first transducer 1 with grub screws, and connecting the end of the second horn 10b to the front plate of the second transducer 2 with grub screws. 【0095】 One method for connecting the squeegee 3 to the first horn 10a and the second horn 10b is to use adhesive. 【0096】 In this way, by connecting the first horn 10a to the first oscillator 1, the second horn 10b to the second oscillator 2, and the squeegee 3 to the first horn 10a and the second horn 10b, vibrations generated in the first oscillator 1 can be transmitted to the squeegee 3 via the first horn 10a, and vibrations generated in the second oscillator 2 can be transmitted to the squeegee 3 via the second horn 10b. 【0097】The first oscillator 1 and the second oscillator 2 are oscillators that excite waves onto the squeegee 3. Metal plates provided on both end faces of the piezoelectric body have positive and negative charges applied to them, respectively. This converts electrical energy into mechanical energy. Specifically, electrical signals are converted into mechanical vibrations, causing the oscillators to vibrate at high frequencies, and these vibrations propagate to the squeegee 3. 【0098】 The function generator 9 sends sinusoidal signals of the same frequency (wavelength) and amplitude, but with a phase shift, to the first oscillator 1 and the second oscillator 2. As a result, the squeegee 3 enters a non-reflective state, where the sinusoidal waves are not substantially reflected. Since the first oscillator 1 and the second oscillator 2 apply an excitation force to the squeegee 3 based on the sinusoidal signals, the squeegee 3 is excited by a traveling wave. This is thought to make it less likely for the sinusoidal standing wave to be generated when the sine wave from the first oscillator 1 is reflected at the other end of the squeegee 3, or when the sine wave from the second oscillator 2 is reflected at one end of the squeegee 3, causing resonance between the wave before reflection and the reflected wave. 【0099】 The squeegee 3 vibrates, for example, at a frequency of 2 kHz to 300 kHz. In other words, the squeegee 3 vibrates at a high frequency near the ultrasonic band. Specifically, when the powder 4 supplied onto the sheet 5 passes through the gap between the squeegee 3 and the sheet 5, the high-frequency vibration of the squeegee 3 is transmitted to the powder 4, increasing the fluidity of the powder 4. As a result, clogging of the powder 4 as it passes through the gap between the squeegee 3 and the sheet 5 is suppressed. This is because, as the squeegee 3 vibrates at a high frequency, the powder 4 in contact with the squeegee 3 is less susceptible to frictional resistance due to powder pressure, thus increasing its fluidity. As a result, the retention and aggregation of the powder 4 are suppressed, and thus clogging of the powder as it passes through the gap between the squeegee 3 and the sheet 5 is suppressed. 【0100】 Furthermore, with respect to the powder 4 located near the squeegee 3, the vibration of the squeegee 3 reduces the frictional force between powder particles and increases fluidity, thereby suppressing the aggregation of the powder 4. 【0101】The fluidity of powder 4 tends to increase with higher vibration frequencies of the squeegee 3. Therefore, by vibrating the squeegee 3 at frequencies of 2 kHz or higher in the high-frequency region near the ultrasonic band, it is expected that the fluidity of powder 4 can be sufficiently increased. However, if the frequency is too high, the vibrations tend to attenuate, making it difficult for the vibrations of the squeegee 3 to propagate through the powder 4. By setting the vibration frequency applied to the squeegee 3 to 300 kHz or lower, the fluidity of powder 4 can be sufficiently increased. 【0102】 As a result, even when using powder 4 with a particle size of 30 μm or less and low fluidity, the vibrating squeegee 3 prevents the powder 4 from accumulating or agglomerating, allowing it to pass through the gap between the squeegee 3 and the sheet 5. Therefore, the film thickness (thickness of the powder layer 8) and the packing density of the powder 4 are standardized. Thus, the powder adjustment unit 11 can form a powder layer 8 with little variation in basis weight. 【0103】 The direction in which the high-frequency vibrations of the squeegee 3 propagate includes at least one of a vertical component and a horizontal component. That is, the squeegee 3 vibrates along at least one of the vertical and horizontal directions. 【0104】 The vertical direction refers to the direction perpendicular to the main surface of the squeegee 3. The main surface of the squeegee 3 is the surface of the squeegee 3 that contacts the powder 4, is parallel to the longitudinal direction of the squeegee 3, and is also the surface of the squeegee 3 that is located on the sheet 5 side. In vertical vibrations, longitudinal waves (waves in the direction of vibration in which the squeegee 3 moves closer to and further away from the powder 4) are easily transmitted to the powder 4. 【0105】 The vertical component of the high-frequency vibration of the squeegee 3 has a significant effect on reducing the frictional resistance between particles of the powder 4. This is because the vertical vibration is in a direction that moves the squeegee 3 closer to and further away from the powder 4, causing repeated collisions between the powder particles 4, and thus making it easier for the vibration to be transmitted to the powder 4. High frequencies generally do not propagate easily, which may make it difficult for vibrations between particles of the powder 4 to be transmitted, but vertical vibrations are particularly effective in transmitting vibrations to the powder 4. 【0106】Furthermore, the horizontal direction is the direction parallel to the main surface of the squeegee 3 and parallel to the axis of the squeegee 3. In horizontal vibrations, transverse waves (waves in the direction in which the squeegee 3 vibrates as it rubs against the powder 4) are easily transmitted to the powder 4. Here, the axis of the squeegee 3 means the axis parallel to the width direction of the sheet 5. The axis of the squeegee 3 may also be parallel to the longitudinal direction of the squeegee 3. 【0107】 The horizontal component of the high-frequency vibration of the squeegee 3 contributes significantly not only to reducing the frictional resistance between particles of the powder 4, but also to reducing the frictional force between the squeegee 3 and the powder 4. If the vertical vibration component is made too large, the vibration will be transmitted too much to the powder 4, causing the powder 4 to vibrate excessively and potentially leading to greater variations in film thickness. However, since the horizontal vibration component can also reduce the frictional force between the squeegee 3 and the powder 4, the fluidity of the powder 4 can be particularly improved. 【0108】 The direction of the high-frequency vibration of the squeegee 3 may be vertical only, or horizontal only. However, if high-frequency vibrations near the ultrasonic band that propagate along both the vertical and horizontal directions are used in combination, the fluidity of the powder 4 can be further improved. For example, when considering a single powder 4, the direction of vibration of the powder 4 given by the squeegee 3 becomes random, and vibration is applied to the entire surface of the powder 4. As a result, there are no surfaces where vibration is not transmitted and frictional resistance is high, and the fluidity of the powder 4 is improved. 【0109】 When the squeegee 3 vibrates vertically and horizontally at high frequencies near the ultrasonic band, the magnitude of the horizontal vibration of the squeegee 3 is greater than, for example, the magnitude of the vertical vibration of the squeegee 3. That is, in the squeegee 3, for example, the magnitude of the transverse wave component of the powder 4 (the direction in which the squeegee 3 vibrates as it rubs against the powder 4) is greater than the magnitude of the longitudinal wave component of the powder 4 (the direction in which the squeegee 3 vibrates as it moves closer to and away from the powder 4). In this case, the frictional resistance at the interface between the squeegee 3 and the powder 4, where frictional resistance tends to be particularly high, can be reduced by the horizontal vibration of the squeegee 3, and the frictional resistance between the particles of the powder 4 can also be reduced. As a result, the fluidity of the powder 4 can be further improved. 【0110】The magnitude of the vertical vibration of the squeegee 3 is, for example, 10 nm or more. That is, the vertical amplitude of the squeegee 3 is, for example, 10 nm or more. In this case, the frictional resistance between the particles of the powder 4 can be sufficiently reduced, and the fluidity of the powder 4 can be further increased. Alternatively, the vertical amplitude of the squeegee 3 can be, for example, 10 μm or less. This prevents the powder 4 from vibrating too much, causing it to scatter as dust and contaminate the surroundings. 【0111】 The magnitude of the horizontal vibration of the squeegee 3 is, for example, 20 nm or more. That is, the horizontal amplitude of the squeegee 3 is, for example, 20 nm or more. In this case, the frictional resistance at the interface between the squeegee 3 and the powder 4 can be sufficiently reduced, and the fluidity of the powder 4 can be further increased. Alternatively, the horizontal amplitude of the squeegee 3 can be, for example, 20 μm or less. This prevents the powder 4 from vibrating too much, causing it to scatter as dust and contaminate the surroundings. 【0112】 The squeegee 3 is, for example, a cylindrical shape with an elongated axial length, and is positioned such that the axial direction of the cylinder (the height direction of the cylinder) is parallel to the upper surface of the sheet 5 and intersects (for example, perpendicular to) the relative movement direction of the sheet 5 with respect to the squeegee 3. The longitudinal direction of the squeegee 3 is the axial direction of the cylinder. In the squeegee 3, the traveling wave propagates in the axial direction. The shape of the squeegee 3 is not particularly limited, and for example, it may be a polygonal prism with a polygonal cross-section. Also, the area of ​​the cross-section of the squeegee 3 does not have to be constant, and the thickness of the squeegee 3 may change along its longitudinal direction. 【0113】 By making the squeegee 3 a cylindrical structure, the axial vibration of the transducer can be efficiently converted into vertical vibration of the squeegee 3. The squeegee 3 can be deformed to reduce the thickness of the cylindrical structure within the squeegee 3. 【0114】 The squeegee 3 may also be a solid cylinder with an elongated axial direction. 【0115】 [Powder coating apparatus] Next, a powder coating apparatus according to this embodiment will be described. 【0116】 The powder coating apparatus comprises a powder adjustment unit 11, a pair of support columns for the squeegee 3 of the powder adjustment unit 11, a drive unit for moving the sheet 5, and a powder supply unit. The powder adjustment unit 11 is positioned such that a gap is formed between the squeegee 3 and the sheet 5. This allows the squeegee 3 to adjust the thickness of the powder 4 supplied onto the sheet 5 by the powder supply unit. The sheet 5 is supported, for example, on a stage. The sheet 5 may also be supported by a conveyor roll or the like. 【0117】 In the powder coating apparatus, the sheet 5 is transported along the direction of travel by a drive unit. The powder coating apparatus continuously supplies powder 4 to the surface of the transported sheet 5 using a powder supply unit. The powder coating apparatus then uses a squeegee 3 to adjust the film thickness and filling rate of the powder 4 supplied to the surface of the sheet 5, thereby achieving the desired basis weight of the powder layer 8 while minimizing variations in basis weight. 【0118】 As described above, traveling waves are propagated through the squeegee 3 in the powder adjustment unit 11. In the powder coating apparatus, the powder 4 is leveled using the vibration of the traveling wave, so variations in the basis weight of the powder layer 8 in the width direction, caused by the antinodes and nodes of the standing wave, can be suppressed. In other words, the powder coating apparatus can form a powder layer 8 with less variation in basis weight in the width direction. 【0119】 The drive unit is, for example, a conveying device that moves the sheet 5 in a predetermined direction. The conveying device is not particularly limited and can be any device as long as it can convey the sheet 5. The conveying device may be, for example, a conveying device that can continuously unwind the sheet 5 wound in a roll shape, or a conveying device that can unwind the sheet 5 intermittently. 【0120】 Furthermore, guide rollers that rotate as the sheet 5 moves, and a control device for correcting the meandering of the sheet 5 may be provided along the conveying path of the sheet 5. Also, the drive unit may be a device that moves the squeegee 3 and the powder supply unit. In other words, the drive unit moves the sheet 5 relative to the squeegee 3 and the powder supply unit in a predetermined direction. 【0121】In this embodiment, the sheet 5 is, for example, a long, strip-shaped thin sheet that is wound up. However, the sheet 5 is not limited to a long, strip-shaped thin sheet. For example, a sheet 5 of a desired shape may be unwound from the conveying device, the powder 4 may be applied to the sheet 5, and then a new sheet 5 may be unwound from the conveying device. Also, the sheet 5 does not have to be wound up in a roll shape. In other words, the sheet 5 only needs to be in a shape that allows the powder 4 to be applied using a powder coating device. For this reason, the shape of the sheet 5 is not particularly limited. 【0122】 The powder supply unit supplies powder 4 to the surface of the sheet 5. In this embodiment, the powder supply unit is, for example, a hopper. The hopper stores powder 4 inside and supplies powder 4 to the surface of the sheet 5. 【0123】 The powder supply unit is positioned upstream of the squeegee 3 in the direction of sheet 5's movement. The powder 4 supplied to the surface of sheet 5 by the powder supply unit reaches the squeegee 3 as sheet 5 moves. In this embodiment, a hopper is used as the powder supply unit, but it is not limited to this; any device capable of supplying powder 4 to the surface of sheet 5 is acceptable. The powder supply unit may be, for example, a feeder such as a screw feeder. 【0124】 In this embodiment, the squeegee 3 is cylindrical, and both axial ends of the cylinder of the squeegee 3 are fixed with bearing-equipped supports so that the squeegee 3 can slide horizontally. The amount of horizontal sliding can be adjusted by attaching a stopper or the like to the squeegee 3. In addition, the axial ends of the cylindrical squeegee 3 are fitted into the diameter of a circular bearing, and the amount of vertical vibration can be adjusted by adjusting the difference between the diameter of the squeegee 3 and the diameter of the bearing. By adjusting the relationship between the horizontal amplitude and the vertical amplitude using this method, it is also possible to create a relationship where the horizontal amplitude is greater than the vertical amplitude. 【0125】Furthermore, the powder coating apparatus does not need to have support columns, as long as it is structured so that a gap is formed between the squeegee 3 and the sheet 5. For example, if the powder adjustment unit 11 is driven by a drive unit, the squeegee 3 may be attached to the drive unit. 【0126】 [Method for Manufacturing the Powder Layer 8] The method for manufacturing the powder layer 8 will be described below. The powder layer 8 can be manufactured using a powder coating apparatus. 【0127】 The method for manufacturing the powder layer 8 includes supplying powder 4 to the surface of a sheet 5, such as a current collector, while moving the sheet 5 in a predetermined direction (powder supply step), and adjusting the thickness and basis weight of the powder layer 8 formed by the powder 4 supplied to the surface of the sheet 5 using a squeegee 3 (powder alignment step). 【0128】 First, powder 4 is prepared. The raw materials for powder 4 are not particularly limited, but for example, a group of particles containing at least one of an active material and a solid electrolyte may be used. When a group of particles containing an active material is used, the active material is mixed with appropriate additives (for example, a binder, a conductive material, and a solid electrolyte) to prepare powder 4. Mixing methods include, for example, mixing in a mortar and pestle, a ball mill, or a mixer. In particular, a method of mixing powder 4 without using solvents is preferred as it does not cause material degradation. 【0129】 In the powder supply process, powder 4 is supplied to the surface of the sheet 5 using a powder supply unit such as a hopper while the sheet 5 is moved in a predetermined direction. The sheet 5 to which the powder 4 is supplied may be in a shape other than a sheet, for example, a plate-shaped or block-shaped base material. In this case, the movement of the base material in the powder supply process may be in the form of intermittently flowing plates or blocks. 【0130】The powder alignment process is a process in which powder 4 is aligned on the surface of the sheet 5 using a squeegee 3 of the powder coating apparatus. In other words, in the powder alignment process, the thickness and basis weight of the powder layer 8 formed by the powder 4 supplied to the surface of the sheet 5 are adjusted using the squeegee 3. As a result, a powder layer 8 with an adjusted basis weight is formed on the sheet 5. At this time, the squeegee 3 vibrates, for example, at a frequency of 2 kHz to 300 kHz. Also, in the squeegee 3, traveling waves propagate from the first oscillator 1 to the second oscillator 2, or from the second oscillator 2 to the first oscillator 1. 【0131】 The method for manufacturing the powder layer 8 may further include a powder sheeting step. The powder sheeting step is a step of compressing the powder layer 8, which is formed by the powder 4 aligned on the sheet 5, through a roll pressing step using a press machine such as a roll press. As a result, a compressed powder layer is formed on the surface of the sheet 5 by compressing the powder layer 8. 【0132】 As described above, in the method for manufacturing the powder layer 8, by performing the powder supply step and the powder alignment step in this order, a powder layer 8 composed of powder 4 is formed on the surface of the sheet 5. Such a laminate of sheet 5 and powder layer 8 can be used in energy devices. For example, when a current collector is used as sheet 5 and a group of particles containing an active material is used as powder 4, electrodes for energy devices can be manufactured. 【0133】 Energy devices manufactured using a powder coating apparatus can have a powder layer 8 with minimal variation in basis weight, which is formed by directly coating the powder 4 after imparting fluidity to it. Therefore, since the method for manufacturing the powder layer 8 involves directly coating the powder 4 without using a process of dispersing the powder 4 in a solvent or the like and then drying it, material degradation due to solvents can be suppressed, leading to the realization of higher capacity energy devices. 【0134】Furthermore, the manufacturing method for the powder layer 8 can suppress the cost increase caused by the use of solvents and the drying of those solvents. Moreover, the manufacturing method for the powder layer 8 can suppress the large amount of energy consumption in the drying process, making it an environmentally friendly manufacturing method. On the other hand, if the basis weight of the powder layer 8 is highly uniform, the quality as an electrode in the energy device can be improved, and a high-capacity energy device with good quality can be manufactured at a low cost. 【0135】 [Powder layer 8] Next, the powder layer 8 formed using a powder coating apparatus will be described. 【0136】 The powder layer 8 according to this embodiment is used, for example, in an energy device. The thickness of the powder layer 8 is, for example, 30 μm or more. The powder layer 8 also contains powder 4 composed of at least one type of particulate material. The concentration of the solvent contained in the powder layer 8 is 50 ppm or less. Furthermore, the variation in basis weight in the powder layer 8 is small. 【0137】 This allows for the formation of a powder layer 8 with minimal variation in basis weight and suppressed degradation by solvents. Furthermore, since solvent drying is not required, energy consumption for drying the solvent can be reduced, thereby reducing environmental impact and preventing increases in manufacturing costs. Therefore, by using such a powder layer 8 in energy devices, it is possible to improve the capacity and quality of energy devices while reducing environmental impact and costs. 【0138】 The powder layer 8 may also be a compressed powder layer formed by pressing the powder layer 8 that was formed by a powder coating apparatus. 【0139】 The powder layer 8 of this embodiment can be used, for example, in an all-solid-state battery. 【0140】 The following describes the details of using the powder layer 8 in an all-solid-state battery. 【0141】 The powder layer 8 is formed, for example, on a sheet 5 which is a current collector, and is used as an electrode (i.e., positive or negative electrode) of an all-solid-state battery. The electrode comprises a current collector and the powder layer 8. 【0142】 The electrode may further include other layers located between the current collector and the powder layer 8. These other layers may be, for example, a connecting layer made of a conductive carbon material. 【0143】 The thickness of the powder layer 8 is 30 μm or more. While there is no particular upper limit to the thickness of the powder layer 8, it is, for example, 2000 μm or less. 【0144】 Furthermore, the powder layer 8 includes powder 4 composed of at least one type of particle material. 【0145】 The concentration of solvent in the powder layer 8 is 50 ppm or less. In other words, the powder layer 8 is substantially free of solvent. Here, "substantially free" means either completely free of solvent or unavoidably present at a concentration of 50 ppm or less as an impurity. The solvent concentration is measured by weight. 【0146】 The size of the powder layer 8 in a plan view is, for example, 30 mm x 30 mm or larger. There is no particular upper limit to the size of the powder layer 8 in a plan view, but the size of the powder layer 8 in a plan view is, for example, 300 mm x 600 mm or smaller. 【0147】 In any 30 mm × 30 mm area on the surface of the powder layer 8, the variation in the basis weight of the powder layer 8 is, for example, 8% or less. 【0148】 The basis weight can be measured using, for example, the following method. First, the powder layer 8 and the current collector are pressed together from above and below to compact them. Then, the powder layer 8 and the current collector are punched out into circles with a diameter of 5 mm to 9 mm, and the total weight of the punched-out powder layer 8 and current collector is measured. Next, the weight of the powder layer 8 is determined by subtracting the weight of the current collector from the same lot, which was previously measured and punched out with a diameter of 5 mm to 9 mm, from the total weight. The basis weight can then be determined by dividing this weight by the area of ​​the punched-out circles with a diameter of 5 mm to 9 mm. 【0149】Furthermore, the variation in basis weight is measured, for example, by the following method. First, an arbitrary 30 mm x 30 mm area is selected on the surface of the powder layer 8 in a plan view. This area may be the central area of ​​the surface of the powder layer 8, or it may include the edges of the powder layer 8. Then, within this area, five or more circular holes are punched out, for example, with a diameter of 5 mm or more and a diameter of 9 mm or less, and the basis weight is measured using the method described above. Nine or more holes may be punched out to improve the accuracy of the variation measurement. The variation in basis weight is calculated by dividing the difference (specifically the absolute value of the difference) between the average basis weight of all punched-out holes and the basis weight of the hole with the largest difference from the average by the average. In other words, a variation in basis weight of 8% or less means that at every punched-out hole, the difference from the average basis weight is 8% or less of the average. 【0150】 As described above, the powder layer 8 is formed by applying high-frequency vibrations to the powder 4 supplied to the surface of the sheet 5, thereby aligning the powder 4 in the powder layer 8 while imparting fluidity to the powder 4. Because the squeegee 3 vibrates with traveling waves, the variation in basis weight in the powder layer 8 is small even in the width direction, making it possible to manufacture high-quality powder layers 8 with a size of 30 mm x 30 mm or more and a thickness of 30 μm or more. For this reason, the powder layer 8 can be used in large, high-capacity energy devices. 【0151】 Furthermore, the powder layer 8 is manufactured, for example, through a coating process that is substantially free of solvents. This makes it possible to form a powder layer 8 that is substantially free of solvents. As a result, the powder layer 8 is not damaged by solvents. Therefore, deterioration of the powder layer 8 is suppressed, and the variation in the basis weight of the powder 4 in the powder layer 8 is small, making it possible to form a powder layer 8 for large, high-capacity energy devices with high capacity and excellent quality. 【0152】 Furthermore, the powder layer 8 can be used, for example, as the positive electrode, negative electrode, or solid electrolyte layer of an energy device such as an all-solid-state battery. 【0153】When the powder layer 8 is used as the positive electrode, for example, the sheet 5 is the positive electrode current collector, and the powder layer 8 containing the powder 4 is the positive electrode mixture layer. In other words, the positive electrode mixture layer is formed on the positive electrode current collector. The powder 4 in the positive electrode mixture layer includes, for example, a positive electrode active material and an ionic conductive solid electrolyte. 【0154】 When the powder layer 8 is used as the negative electrode, for example, the sheet 5 is the negative electrode current collector, and the powder layer 8 containing the powder 4 is the negative electrode mixture layer. In other words, the negative electrode mixture layer is formed on the negative electrode current collector. The powder 4 in the negative electrode mixture layer includes, for example, a negative electrode active material and a solid electrolyte having ionic conductivity. 【0155】 When the powder layer 8 is used as a solid electrolyte layer, for example, the powder layer 8 containing the powder 4 is a solid electrolyte layer. The solid electrolyte layer is formed on the surface of the positive electrode mixture layer formed on the positive electrode current collector or on the surface of the negative electrode mixture layer formed on the negative electrode current collector. In other words, the sheet 5 is, for example, a positive electrode mixture layer formed on the positive electrode current collector or a negative electrode mixture layer formed on the negative electrode current collector. The powder 4 in the solid electrolyte layer contains, for example, a solid electrolyte having ionic conductivity. 【0156】 The concentration of solvent in the positive electrode mixture layer, negative electrode mixture layer, and solid electrolyte layer described above is 50 ppm or less. In other words, the positive electrode mixture layer, negative electrode mixture layer, and solid electrolyte layer are substantially solvent-free. Here, "substantially solvent-free" means either when these layers contain no solvent at all, or when these layers inevitably contain 50 ppm or less of solvent as impurities, etc. 【0157】Incidentally, the solvent is, for example, an organic solvent. The method for measuring the solvent is not particularly limited, and it can be measured using, for example, gas chromatography, the mass change method, or the like. Examples of organic solvents include nonpolar organic solvents such as heptane, xylene, and toluene, polar organic solvents such as tertiary amine solvents, ether solvents, thiol solvents, and ester solvents, and combinations thereof. Examples of tertiary amine solvents include triethylamine, tributylamine, and triamylamine. Examples of ether solvents include tetrahydrofuran and cyclopentyl methyl ether. Examples of thiol solvents include ethanethiol. Examples of ester solvents include butyl butyrate, ethyl acetate, and butyl acetate. 【0158】 Next, details of the materials used for the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer will be described. 【0159】 The positive electrode active material is a substance in which metal ions such as lithium (Li) are inserted or removed into or from the crystal structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs with the insertion or removal of metal ions such as lithium. The type of positive electrode active material is appropriately selected according to the type of all-solid-state battery, and examples include oxide active materials and sulfide active materials. 【0160】 In the present embodiment, an oxide active material (lithium-containing transition metal oxide) is used as the positive electrode active material. Examples of oxide active materials include LiCoO ２ , LiNiO ２ , LiMnO ２ O ４ , LiCoPO ４ , LiNiPO ４ , LiFePO ４ , LiMnPO ４ and compounds obtained by substituting the transition metal of these compounds with one or two different elements, and the like. Examples of compounds obtained by substituting the transition metal of the above compounds with one or two different elements include LiNi １／３ Co １／３ Mn １／３ O ２ , LiNi ０．８ Co ０．１５ Al ０．０５ O２ LiNi ０．５ Mn １．５ O ２ Known materials such as those listed above can be used. The positive electrode active material may be used alone or in combination of two or more types. 【0161】 Examples of the positive electrode active material's shape include particulate matter. When the positive electrode active material is particulate, its particle size may be, for example, in the range of 50 nm to 30 μm, or in the range of 1 μm to 15 μm. If the particle size of the positive electrode active material is 50 nm or larger, handling is generally improved. On the other hand, if the particle size is 30 μm or smaller, using a small-particle active material increases the surface area, making it easier to obtain a high-capacity positive electrode. In this specification, the particle size of the material contained in the positive electrode mixture layer or negative electrode mixture layer is, for example, D50 as described above. 【0162】 The surface of the positive electrode active material may be covered with a coating layer. This is because it can suppress the reaction between the positive electrode active material (e.g., oxide active material) and the solid electrolyte (e.g., sulfide-based solid electrolyte). Examples of coating layer materials include LiNbO ３ Li ３ PO ４ Examples include Li-ion conductive oxides such as LiPON. The average thickness of the coating layer is, for example, in the range of 1 nm to 20 nm, or in the range of 1 nm to 10 nm. 【0163】 The ratio of positive electrode active material to solid electrolyte in the positive electrode mixture layer may be within the range of 1 to 99, or within the range of 23 to 19, when calculated by weight as positive electrode active material / solid electrolyte = weight ratio. This range of weight ratio makes it easier to ensure both lithium ion conduction pathways and electron conduction pathways within the positive electrode mixture layer. 【0164】 The negative electrode active material is a substance in which metal ions such as lithium are inserted into or removed from its crystal structure at a lower potential than that of the positive electrode, and oxidation or reduction occurs in conjunction with the insertion or removal of these metal ions. 【0165】In this embodiment, the negative electrode active material may be, for example, easily alloyable metals with lithium such as lithium, indium, tin, and silicon, carbon materials such as hard carbon and graphite, and Li ４ Ti ５ O １２ SiO ｘ Known materials such as oxide active materials can be used. Furthermore, composite materials obtained by appropriately mixing the above-mentioned negative electrode active materials may also be used as the negative electrode active material. 【0166】 The particle size of the negative electrode active material is, for example, 30 μm or less. By using an active material with a small particle size, the surface area is increased, and a high volume can be achieved. 【0167】 The ratio of negative electrode active material to solid electrolyte contained in the negative electrode mixture layer, when calculated by weight as negative electrode active material / solid electrolyte = weight ratio, may be, for example, in the range of 0.6 to 19, or in the range of 1 to 9. This weight ratio range makes it easier to ensure both lithium ion conduction pathways and electron conduction pathways within the negative electrode mixture layer. 【0168】 The solid electrolyte can be appropriately selected depending on the conductive ion species (e.g., lithium ions). Examples of solid electrolytes include sulfide-based solid electrolytes, oxide-based solid electrolytes, and halide-based solid electrolytes. 【0169】 The type of sulfide-based solid electrolyte in this embodiment is not particularly limited, but examples of sulfide-based solid electrolytes include Li ２ S-SiS ２ LiI-Li ２ S-SiS ２ LiI-Li ２ S-P ２ S ５ LiI-Li ２ S-P ２ O ５ LiI-Li ３ PO ４ -P ２ S ５ and Li ２ S-P ２ S ５Examples include the above. In particular, from the viewpoint of excellent lithium ion conductivity, the sulfide-based solid electrolyte may contain Li, P, and S. The sulfide-based solid electrolyte may be used alone or in combination of two or more types. Furthermore, the sulfide-based solid electrolyte may be crystalline, amorphous, or glass ceramic. Note that the above "Li ２ S-P ２ S ５ The description of " is Li ２ S and P ２ S ５ This refers to a sulfide-based solid electrolyte using a raw material composition containing [specific ingredient], and the same applies to other descriptions. 【0170】 In this embodiment, one form of the sulfide-based solid electrolyte is Li ２ S and P ２ S ５ It is a sulfide glass ceramic containing Li ２ S and P ２ S ５ The proportion of Li is expressed in moles. ２ S / P ２ S ５ = When expressed as a molar ratio, for example, the molar ratio may be in the range of 2.3 to 4, or it may be in the range of 3 to 4. By being within this molar ratio range, it is possible to achieve a crystal structure with high ion conductivity while maintaining the lithium concentration that affects battery characteristics. 【0171】 In this embodiment, the shape of the sulfide-based solid electrolyte can be, for example, a spherical or ellipsoidal particle shape. When the sulfide-based solid electrolyte material is in the form of particles, the particle size of the sulfide-based solid electrolyte is not particularly limited, but it may be 30 μm or less, 20 μm or less, or 10 μm or less, as it makes it easier to improve the packing efficiency in the positive or negative electrode. On the other hand, the particle size of the sulfide-based solid electrolyte may be 0.001 μm or more, or 0.01 μm or more. 【0172】 Next, the oxide-based solid electrolyte in this embodiment will be described. The type of oxide-based solid electrolyte is not particularly limited, but LiPON, Li... ３ PO ４Li ２ SiO ２ Li ２ SiO ４ Li ０．５ La ０．５ TiO ３ Li １．３ Al ０．３ Ti ０．７ (PO ４ ) ３ La ０．５１ Li ０．３４ TiO ０．７４ Li １．５ Al ０．５ Ge １．５ (PO ４ ) ３ Examples include the following. The oxide-based solid electrolyte may be used individually or in combination of two or more types. 【0173】 Next, we will describe the details of the positive electrode current collector and the negative electrode current collector. 【0174】 The positive electrode in this embodiment includes a positive electrode current collector made of, for example, a metal foil. The positive electrode current collector can be a foil-like body, plate-like body, mesh-like body, etc., made of, for example, aluminum, gold, platinum, zinc, copper, stainless steel (SUS), nickel, tin, titanium, or an alloy of two or more of these. 【0175】 Furthermore, the thickness and shape of the positive electrode current collector may be appropriately selected depending on the application of the positive electrode. 【0176】 In this embodiment, the negative electrode includes a negative electrode current collector made of, for example, a metal foil. The negative electrode current collector can be made of, for example, stainless steel (SUS), gold, platinum, zinc, copper, nickel, titanium, tin, or an alloy of two or more of these materials, in the form of a foil, plate, mesh, etc. 【0177】 Furthermore, the thickness and shape of the negative electrode current collector may be appropriately selected depending on the application of the negative electrode. 【0178】(Other Embodiments) The powder preparation unit according to the present disclosure has been described above based on embodiments, but the present disclosure is not limited to these embodiments. Without departing from the spirit of the present disclosure, various modifications to the embodiments that a person skilled in the art can conceive of, and other forms constructed by combining some of the components of the embodiments are also included in the scope of the present disclosure. 【0179】 For example, in the above embodiment, the squeegee 3 vibrated at a high frequency near the ultrasonic band, but it is not limited to this. The vibration frequency of the squeegee 3 can be set according to the characteristics of the powder 4, and may be, for example, 2 kHz or less. 【0180】 For example, although we have described a method of connecting the first horn 10a and the second horn 10b from the inside of the squeegee 3, it is also acceptable to connect the first horn 10a and the second horn 10b from the outside of the squeegee 3. 【0181】 The powder preparation unit according to this disclosure can form a uniform powder layer with little variation in film thickness without using solvents, and can therefore be used to form various powder layers, such as the composite layer of high-quality all-solid-state batteries. 【0182】 1. First transducer 2. Second transducer 3, 23. Squeegee 3a, 3b. Aperture 4, 24. Powder 5, 25. Sheet 6. First amplifier 7. Second amplifier 8, 28. Powder layer 9. Function generator 10a. First horn (joint) 10b. Second horn (joint) 11. Powder adjustment unit 30. Powder coating apparatus

Claims

1. A powder adjustment unit comprising: a hollow squeegee; a first horn connected to one side of the squeegee; a second horn connected to the other side of the squeegee; a first vibrator for exciting the squeegee with waves; and a second vibrator for exciting the squeegee with waves, wherein both ends of the squeegee are open ends; the first vibrator is connected to the one side of the squeegee via the first horn; the second vibrator is connected to the other side of the squeegee via the second horn; and the first vibrator and the second vibrator vibrate such that the phase of the wave excited by the first vibrator and the wave excited by the second vibrator are different.

2. The powder adjustment unit according to claim 1, wherein the first horn is inserted through an opening formed on one side of the squeegee and connected inside the squeegee, the second horn is inserted through an opening formed on the other side of the squeegee and connected inside the squeegee, the one side of the squeegee is connected to the first horn in a range from one end of the squeegee to at least one-third of the wavelength of the wave excited by the first vibrator and at least two-thirds of the wavelength of the wave excited by the first vibrator, and the other side of the squeegee is connected to the second horn in a range from the other end of the squeegee to at least one-third of the wavelength of the wave excited by the second vibrator and at least two-thirds of the wavelength of the wave excited by the second vibrator.

3. The powder adjustment unit according to claim 2, wherein the first horn has a first connecting portion connected inside one side of the squeegee, the second horn has a second connecting portion connected inside the other side of the squeegee, and the width of the first connecting portion connected to the squeegee and the width of the second connecting portion connected to the squeegee are each 1 / 30 to 1 / 9 of the wavelength of the wave excited by the first and second transducers.

4. The first horn further has a first main body connected to the first connecting portion on the side of the first connecting portion opposite to the squeegee side, the second horn further has a second main body connected to the second connecting portion on the side of the second connecting portion opposite to the squeegee side, the first main body has a first large diameter portion connected to the first transducer and a first small diameter portion disposed between the first transducer and the first large diameter portion and having a smaller diameter than the first large diameter portion, the second main body has a second large diameter portion connected to the second transducer and a second small diameter portion disposed between the second transducer and the second large diameter portion and having a smaller diameter than the second large diameter portion, the outer diameter of the first small diameter portion is 7 / 15 or more and 4 / 5 or less of the outer diameter of the first main body, the outer diameter of the second small diameter portion is 7 / 15 or more and 4 / 5 or less of the outer diameter of the second main body, and the total length of the first large diameter portion and the total length of the first small diameter portion are approximately equal. The powder adjustment unit according to claim 3, wherein the total length of the second large diameter portion and the total length of the second small diameter portion are approximately equal.

5. The powder adjustment unit according to claim 4, wherein the outer diameter of the first connecting portion is 2 / 3 of the outer diameter of the first main body, and the outer diameter of the second connecting portion is 2 / 3 of the outer diameter of the second main body.

6. The powder adjustment unit according to claim 4, wherein the outer diameter of the first large-diameter portion is approximately equal to the outer diameter of the first vibrator, and the outer diameter of the second large-diameter portion is approximately equal to the outer diameter of the second vibrator.

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