JPH038238A - Electrodepositing method - Google Patents

Abstract

PURPOSE:To improve the electrodeposition quality and manufacturing process by immersing fixed-size substrates arranged with many segment electrodes in multiple rows and cut off for individual rows in the post-process in an electrodeposition liquid together with mating electrodes, and electrodepositing phosphor grains. CONSTITUTION:Mating electrodes 16 arranged face to face in parallel with segment electrodes 11 of fixed-sized substrates 10 set on rotors 12 and applied with the voltage across them are provided on the lower faces of rotors 12. The electric field for electrodeposition is formed between the electrode 16 on the upper side and the electrode 11 on the lower side between rotors 12. The relative movement between the substrates 10 and an electrodeposition liquid 15 is performed by the movement of the substrates 10 by the rotation of the rotors 12. Phosphor grains are concurrently stuck on the electrodes 11 of multiple substrates 10 by electrodeposition. Most of the processes of segment electrode formation, insulating layer formation, fluorescent screen formation and bulb formation are performed while the substrates 10 are arranged, and individual substrates 10 may be cut off in a bulb size for each segment electrode row in the final process of electrodeposition and bulb formation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrodeposition method applied to the formation of phosphor screens in fluorescent display tubes, dot array fluorescent tubes, and the like.

Conventional technology Conventionally, in a fluorescent display tube, a fluorescent screen is formed on a large number of segment electrodes formed in an array in one direction, and the fluorescent screen is sealed together with a hot cathode in a vacuum container, and the hot cathode generates thermionic electrons. , a positive voltage is selectively applied to the segments mN according to the information to be displayed to attract thermoelectrons to the selected segment electrodes, and the attracted thermoelectrons emit fluorescence when they collide with the phosphor screen. A device that displays information, and is known as a barcode display tube or dot array fluorescent tube.

In such a fluorescent display tube, as a method of forming a good fluorescent screen on the segment electrodes, for example,
A method using electrophoresis is known, as shown in Japanese Patent No. 55728. In this method, an electrodeposited substrate on which a segment electrode array is formed is immersed in a dispersion liquid in which phosphor particles are dispersed, and a voltage is applied between the segment electrode array and a counter electrode facing the segment electrode array. This creates an electric field to cause the phosphor particles in the dispersion to adhere to the segment electrodes. Here, the counter electrode and the segment electrode array are arranged parallel to each other and facing each other.

Furthermore, when looking at the gap between these electrodes, the so-called opposing gap, from the viewpoint of electric field, the smaller the gap, the greater the electric field intensity can be obtained even if the applied voltage is small. In the electrophoresis method, dispersed particles move in a liquid in response to the electric field strength, so the electric field strength is a very important factor.

However, it is extremely difficult to control the phosphor particles only on the segment electrode rows and not on other parts using an electric field alone. It has been empirically found that scraping and removing is effective.

Therefore, there are devices in which a liquid flow is generated by stirring the inside of the liquid layer with a rotary blade, for example, a propeller-shaped stirring member, or by circulating the liquid with a pump or the like. However, there is a limit to the stability of the flow, and especially when the electrode surface size is large or the segment electrode arrangement density is large, a dispersion liquid of a predetermined concentration cannot be stably supplied to the gap between the opposing electrodes.
There is a problem in that dense adhesion of the phosphor particles to the segment electrodes cannot be expected.

Various methods have been proposed to solve these problems. For example, according to Japanese Patent Application No. 61-134280 and Japanese Patent Application No. 62-178484, Figures 11 and 12
As shown in the figure, in order to electrodeposit phosphor particles on a large number of segment electrodes 2 arranged in an electrodeposition substrate 11-, an electrodeposition liquid 3 containing dispersed phosphor powder is accommodated in an electrodeposition N4. A plurality of electrodeposited substrates 1 are mounted around a rotating shaft 5 provided in this electrodeposition tank 4.
A method is shown in which the stability of liquid stirring by the diffusion blade 7 is increased by configuring the phosphor particles into a polygonal shape via the holding member 6, and the phosphor particles are densely adhered only to the segment electrodes 2. 8 is a counter electrode disposed opposite to each segment electrode 2, and a power source 9 is connected between the segment electrode 2 and the segment electrode 2.
A voltage is applied by.

According to such an electrodeposition apparatus or method, it is possible to perform electrodeposition on a large number of substrates 1 at the same time, in addition to stable liquid stirring and dense adhesion of phosphor particles, which is efficient.

Problems to be Solved by the Invention The proposed method has the advantage of being able to electrodeposit multiple substrates at once, but since the electrodeposited substrates form a polygonal shape, the entire electrodeposition apparatus needs to be Due to size constraints, the size of the minus electrodeposited substrate 1 cannot be increased too much. Usually, a plurality of substrates of a desired size are cut out from a somewhat large-sized substrate called a "standard size substrate", and in the case of a single electrodeposited substrate l as described above, a regular size substrate is used. For example, it is common to use substrates cut into about 5 to 20 sheets. Considering the entire manufacturing process of fluorescent tubes, etc., it is advantageous in terms of quality stabilization, automation, transportability, etc. to carry out the cutting of the board from a standard size board to the size of a tube as late as possible. There are many. However, considering the manufacturing process using the electrodeposition method shown in FIG. 11, etc., the steps from "segment electrode formation" to "insulating layer formation" are performed on a regular size substrate, and then "cutting of the regular size substrate" is performed. After cutting the board to the tube size using [
Phosphor screen formation (electrodeposition) → "Tube formation J process will be performed to the size of the tube. In this way, it is not desirable to cut the substrate at the previous stage of the manufacturing process, such as immediately before electrodeposition. .

In addition, electrodeposition of phosphor particles by electrophoresis uses an electrodeposition liquid in which phosphor particles are dispersed, and an electric field is formed between a segment electrode and a counter electrode to be electrodeposited. This method selectively attaches phosphor particles only to the electrodes,
After electrodeposition, when the substrate is pulled up from the electrodeposition solution, the electrodeposition solution at the top flows to the bottom and remains between the segment electrodes, or when it comes out into the air, the adhered phosphor particles are disturbed. Sometimes.

Means for Solving the Problems In the invention as set forth in claim 1, a large number of segment electrodes and a counter electrode arranged in an array on an electrodeposition substrate are immersed in an electrodeposition liquid in which phosphor particles are dispersed. In the electrodeposition method, an electric field is formed between the segment electrode and an electrode facing the Mjf surface to electrodeposit phosphor particles on the segment electrode. A regular size substrate cut into rows is immersed in an electrodeposition solution together with a counter electrode, and the regular size substrate and 1
The phosphor particles were simultaneously electrodeposited on each segment electrode in each row by moving the electrodeposition liquid relatively to the electrodeposition liquid No. 11.

In the invention according to claim 2, the segment electrodes and the counter electrode are immersed in an electrodeposition liquid in which phosphor particles are dispersed. In the electrodeposition method, the phosphor particles are electrodeposited on the segment electrodes by forming an electric field between them and a counter electrode, and after the electrodeposition, the electrodeposition substrate is pulled up from the electrodeposition solution and dried. The attitude of the electrodeposited substrate was controlled so that at least during the pulling process from the electrodeposition solution, the plane containing the surface of the electrodeposited substrate and the pulling direction were not perpendicular to each other.

According to the invention described in claim 1, phosphor particles are simultaneously formed by electrophoresis on a plurality of rows of segment electrodes on a regular size substrate, and in a post process, the regular size substrate is divided into multiple rows of segment electrodes. They can be cut into functional devices, making the manufacturing process advantageous.

According to the invention as claimed in claim 2, when the electrodeposited substrate is pulled up from the electrodeposition solution after electrodeposition, the plane containing the electrodeposition substrate and the pulling direction are not perpendicular to each other, so that the electrodeposited substrate with attached phosphor particles is removed. When the surface exits into the air, no turbulence occurs and quality deterioration is prevented.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

First, the substrate of this embodiment to be subjected to electrodeposition is a regular size substrate 1, O as shown in FIG. In the illustrated example, 6 rows of 11 segment electrodes are formed, each of which is cut at the part shown by the red line in the post process after tube formation, and each of the segments shown in keys 1 to 6 constitutes one functional element. The case of taking is shown. That is, the term "regular size substrate" as used in the present invention refers to a substrate provided with a plurality of rows of a large number of segment electrodes 11 for constructing one functional device in this way.

In this embodiment, electrodeposition is performed using such a standard size substrate 10 as it is.

First, a disk-shaped rotary body 12 is provided on which a plurality of such regular size substrates 10 are set in a detachable manner. In this embodiment, as shown in FIG. 1, four regular-sized substrates 10 can be set in symmetrical positions in a detachable manner. As shown in FIG.
3 are provided in parallel in multiple stages in the electrodeposition bath 14 and immersed in the electrodeposition liquid 15. Here, on the lower surface of each rotating body 12, there is provided a counter electrode 16 that faces parallel to the segment electrode 11 of the standard size substrate 10 set on the rotating body 12 below, and to which a voltage is applied between both presses. It is being For this reason, as shown in FIG. 3, the uppermost rotating body 12 does not have a counter electrode that should be opposed above it, and therefore no regular size substrate is mounted thereon. As a result, between each rotating body 12, an electric field for electrodeposition is formed between the opposing electrode 6 on the upper side and the segment electrode 11 on the lower side. The relative movement between the regular size substrate 10 and the electrodeposition liquid 15 is caused by the movement of the regular size substrate 10 due to the rotation of the rotating body 12 driven by the rotating shaft 13.

With such an electrodeposition device, a plurality of regular size substrates 1
The deposition of phosphor particles by electrodeposition onto each segment electrode ll of 0 is performed simultaneously. That is, most of the steps up to "segment electrode formation,""insulating layer formation,""phosphor screen formation," and "tube formation" are performed on the standard size substrate 10, and the final process of electrodeposition and tube formation is performed as is. , it is sufficient to cut each regular size substrate 10 into tube size pieces for each segment electrode row. Therefore, it is advantageous in terms of quality stabilization, automation, transportability, etc. in the manufacturing process.

By the way, during electrodeposition as shown in FIGS. 1 and 3, since the segment electrode 1 is provided on almost the entire surface of the regular-sized substrate O, it is possible to electrodeposit uniformly over almost the entire surface of the substrate. It becomes necessary. Here, it has been known that the electrodeposition quality can be varied by changing parameters such as the gap between the segment electrode 11 and the counter electrode 16, the applied voltage, the voltage application time, and the rotation speed of the rotating body 12. It is the same as the electrodeposition method currently being used, and the optimum condition is water fi.
11'.

These parameters are set by a combination of .

Now, in the case of the method shown in FIG. 1, a somewhat large regular-sized substrate 10 is placed on a disc-shaped rotating body 12, and since the rotating body 12 rotates, the segment electrodes on the regular-sized substrate 10 Since the moving speed differs depending on the position of the inner and outer periphery of the row No. 11 (for example, those of Kan 6 on the innermost periphery and those of Seed 1 on the outermost periphery), the supply of phosphor particles onto segment electrode +1, Or, conversely, the scavenge ability of the phosphor particles differs.

Therefore, the quality of the electrodeposition differs between the portion of the scale 1 and the portion of the affected area 6. Therefore, such a regular size substrate 10
In order to obtain a uniform electrodeposited crystal over almost the entire surface, the diameter of the rotating body 12 may be increased and the parameters of the pond may be fixed to such an extent that the speed difference between the position 1 and the position 6 can be ignored.
Alternatively, the difference in electrodeposition ability due to the speed difference depending on the inner and outer peripheral positions of the segment electrode array may be compensated for by other parameters (for example, applied voltage, voltage application time, gap between electrodes, etc.).

In any case, in the case of the method of this embodiment, the device size must be increased somewhat in the plane direction, but the number of stages of the rotating body 12 is increased accordingly, and it is necessary to If electrodeposition can be done all at once, there will be no problem with productivity.

In this example, the regular size substrate 10 side was moved by the rotating body 12 in the electrodeposition liquid 15 for electrodeposition, but the regular size substrate 10 (therefore, the rotating body 12) side was fixed and the stirring was performed. The electrodeposition liquid 15 side may be moved using a blade or the like.

Furthermore, in addition to the basics of the electrodeposition method described above, for example, 1!
In order to prevent the formation of a particle size distribution of phosphor particles in the deposited liquid (larger particles are present in the lower layer), methods such as stirring or circulating the electrodeposition solution are used, and electrodeposition due to foreign matter In order to prevent quality deterioration, it is preferable to take measures such as providing liquid filtering means.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. In this embodiment, a plurality of regular size substrates 10, for example six, are formed into a polygonal shape by a holding member 17 and are immersed in an electrodeposition solution. More specifically, each regular size substrate 10 has a segment electrode 1
The column 1 is vertical and is arranged vertically in the inner position, with l for each segment @111 column.
:1, the counter electrode 18 is supported by the holding member 17 and provided. At the center of the polygonal shape formed by these regular-sized substrates 1O, there is provided a rotating shaft 2o that is equipped with stirring blades 19 and that stirs and moves the electrodeposition liquid.

In such a configuration, when the stirring blade 19 rotates in the direction of the arrow, a uniform flow of the electrodeposition liquid occurs on the surface of each segment electrode 11, and uniform electrodeposition quality can be obtained by appropriately setting the parameters as described above. It will be done. Depending on the actual configuration, the flow characteristics of the electrodeposition liquid may differ slightly for each segment electrode row, but in such a case, the flow characteristics of the electrodeposition liquid may differ slightly depending on the actual configuration. It is possible to compensate by appropriately setting parameters other than flow. In addition to stirring the electrodeposition liquid side, it is also possible to move the standard size substrate 10 side relative to the electrodeposition liquid.

Furthermore, a third embodiment of the present invention will be explained with reference to FIG. The following examples relate to the posture of the electrodeposited substrate in the electrodeposition solution or the posture when it is pulled up from the jMXX solution for the drying process. A regular size board 10 may be used, but a regular size board 10 may be used.
A single electrodeposited substrate 2 may be used, including these.
This will be explained as 1.

The basic structure of the electrodeposition apparatus is similar to that of the first embodiment, and an electrodeposition tank 14 containing an electrodeposition liquid 15 and an electrodeposition substrate 21 are set and rotated by a rotating shaft 13. It consists of a rotating body 12.

In this embodiment, the rotating shaft 13 is tilted at an angle θ with respect to the pulling direction (vertical direction) A, and each rotating body 12 is also tilted at an angle 0 with respect to the horizontal plane. ing. Electrodeposition is performed by being immersed in the electrodeposition liquid 15 in such an inclined state.

After electrodeposition, the rotating body 12 is pulled up together with the rotating shaft 13 in the direction shown by arrow A, but due to the above-mentioned tilted state, the surface direction of the electrodeposited substrate 21 is not perpendicular to this pulling direction. Thereby, when the electrodeposition surface of the electrodeposition substrate 21 exits from the electrodeposition liquid 15 into the air, no disturbance occurs. Further, the load during pulling is also reduced compared to when the rotating body 12 is perpendicular to the pulling direction A.

Further, a fourth embodiment of the present invention will be explained with reference to FIG.

In this embodiment, the rotating body 12 is
is installed at an angle of θ.

With such a configuration, when the rotating body 12 is rotated by the rotating shaft 13, the electrodeposition substrate 21 on the rotating body 12 rotates while moving up and down, and is electrodeposited on the segment electrode.

Therefore, during electrodeposition, the effect of stirring the electrodeposition liquid is also exhibited. After electrodeposition, if it is pulled up in the direction A shown by the arrow, that is, in the axial direction of the rotating shaft 13, the electrodeposited surface of the electrodeposited substrate 21 and the pulling direction will not be perpendicular to each other, and the electrodeposited surface will not be disturbed.

Furthermore, a fifth embodiment of the present invention will be explained with reference to FIG. In this embodiment, instead of the planar rotating body 12, an umbrella-shaped rotating body 22 which is curved downward toward the outer circumference is used.

Next, a sixth embodiment of the present invention will be explained with reference to FIG. 9 and FIG. 1O. In this embodiment, as in the previous embodiment, the rotating body 2
This is a modified version of the shape of 3.

Basically, it has a planar shape, but as shown in FIG. 10, which shows a partially enlarged view, each electrodeposited substrate 21 is installed at an angle so that the cooler side of the flow B of the electrodeposited liquid 15 is higher. An inclined portion 23a inclined by O is formed. Further, the lower surface side of the rotating body 23 is also formed in an inclined shape corresponding to the inclined part 23a,
A counter electrode 24 is attached to a portion facing the electrodeposited substrate 21 so as to face the substrate 2 in parallel.

According to this embodiment, as the rotating bodies 23 rotate during electrodeposition, there is a distance of 100 mm between each of the rotating bodies 23, as shown in FIG.
A flow B of the electrodeposition liquid 15 is generated, which moves while moving, and a stirring effect is also exerted, resulting in good electrodeposition. At the time of pulling up after electrodeposition, the electrodeposited surface is not perpendicular to the pulling direction A and no disturbance occurs, as in the case of the multiplexed embodiments.

In addition, in these third to sixth embodiments, when pulling up the electrodeposited substrate 21 after free deposition, the electrodeposition substrate 21 and the electrodeposition liquid 1 are
5 and 5 may be carried out while moving relative to each other in the same manner as during electrodeposition, or may be carried out while the movement is stopped, and this may be determined in relation to the electrodeposition quality, electrodeposition conditions, etc.

Effects of the Invention Since the present invention is configured as described above, according to the invention described in claim 1, segment electrodes in multiple rows on a regular size substrate can be obtained! Phosphor particles are simultaneously formed on top of the electrode by electrophoresis, and in the post-electrodeposition process, the standard size substrate can be cut into segment electrode rows to form functional devices. It is possible to make the manufacturing process advantageous in addition to the quality, and according to the invention set forth in claim 2, when the electrodeposited substrate is removed from the electrodeposition solution after electrodeposition, the electrodeposition substrate is removed. Since the containing plane and the pulling direction are not perpendicular to each other, turbulence is prevented when the electrodeposited surface with phosphor particles comes out into the air, thus maintaining the electrodeposited quality of the electrodeposited substrate subjected to the drying process. can do.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the first embodiment of the present invention, FIG. 2 is an enlarged plan view of a standard size substrate, FIG. 3 is a schematic sectional view showing an electrodeposition apparatus, and FIG. A schematic plan view showing the second embodiment of the invention, FIG. 5 is a longitudinal sectional side view of a part thereof, and FIG.
The figure is a schematic step view showing a third embodiment of the present invention, FIG. 7 is a schematic step view showing a fourth embodiment of the present invention, and FIG. 8 is a schematic step view showing a fifth embodiment of the present invention. FIG. 9 is a schematic step view showing the sixth embodiment of the present invention, FIG. 10 is an enlarged step view of a part thereof, and FIG. 11 is a horizontal cross section showing the conventional example. 12 are longitudinal sectional side views thereof.

Claims (1)

[Scope of Claims] 1. While a large number of segment electrodes and a counter electrode arranged in an array on an electrodeposition substrate are immersed in an electrodeposition liquid in which phosphor particles are dispersed, the segment electrodes and the counter electrode are In this electrodeposition method, phosphor particles are electrodeposited on the segment electrodes by forming an electric field between the segment electrodes. The sized substrate was immersed in an electrodeposition solution together with a counter electrode, and the regular sized substrate and the electrodeposition solution were moved relative to each other so that phosphor particles were simultaneously electrodeposited onto each segment electrode in each row. An electrodeposition method characterized by: 2. With a large number of segment electrodes arranged and formed on an electrodeposition substrate and a counter electrode immersed in an electrodeposition liquid in which phosphor particles are dispersed, an electric field is applied between the segment electrodes and the counter electrode. phosphor particles are electrodeposited on the segment electrodes, and after the electrodeposition, the electrodeposition substrate is pulled up from the electrodeposition solution and dried. An electrodeposition method characterized in that the attitude of the electrodeposition substrate is controlled so that a plane including the surface of the electrodeposition substrate and the pulling direction are not perpendicular to each other during the process.