JPH06182980A - Printing device due to ink jet printer - Google Patents

Abstract

PURPOSE:To enhance printing accuracy and printing sharpness by eliminating the effect of a wind. CONSTITUTION:A printing device is constituted of an ink jet printer applying printing to a material 6 to be printed, a hermetically closed printing chamber 7 receiving the material to be printed and at least the nozzle 1 of the ink jet printer to perform printing and a vacuum device 8 reducing the pressure in the hermetically closed printing chamber 7. A wind is hard to be generated in the hermetically closed printing chamber 7 held to a thin air vacuum state and the possibility receiving the effect of a wind is eliminated. The evaporation speed of the diluent of ink is accelerated in the hermetically closed printing chamber 7 held to a vacuum state to make it possible to accelerate the drying of the ink and the blur of the ink can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device such as an ink jet printer for printing a printed wiring board.

[0002]

2. Description of the Related Art Product numbers, lot numbers, company symbol marks, etc. are printed on the surface of printed materials such as printed wiring boards and electronic parts.
In order to print a bear mark or the like, or to print a resist, a conductive paste, a core of electroless plating, or the like on the surface of them, conventionally, screen printing is generally performed. However, in the case of screen printing, it is necessary to make a screen plate, and even in the case of producing a large amount of a small amount of products, there is a problem that such a plate making results in poor work efficiency and high cost.

Therefore, it has been proposed by the applicant that printing is performed by printing on the surface of an object to be printed using an ink jet printer. Inkjet printers are capable of printing with arbitrary characters, etc. according to the input data to the computer without the need to use a plate. Moreover, inkjet printers make ink particles fly from the nozzles to the surface of the substrate to be printed. Since the printing is performed by adhering it on, it does not impact the surface of the material to be printed like a wire dot printer, and even if there is some unevenness on the surface, printing can be done without problems. Therefore, it is most suitable as an apparatus for printing on an object to be printed such as a printed wiring board having a circuit formed on the surface.

When printing with an ink jet printer, it is necessary to scan the nozzles over the entire surface of the material to be printed by moving and moving the material to be printed at a high speed relative to the nozzles of the ink jet printer.

[0005]

However, when the printing material is run at a high speed as described above, wind is generated along with the running, and the flight direction of the ink particles flying from the nozzle to the printing material is affected. Therefore, there is a possibility that accurate printing cannot be performed. In addition, since the ink jet printer is used by ejecting the ink into particles, the ink is used by reducing the viscosity with a diluent, and after the ink particles are attached to the surface of the printed material, the ink is applied to the printed material by the diluent. There is also a problem that the ink penetrates to cause bleeding, resulting in poor print definition.

The present invention has been made in view of the above points, and provides a printing apparatus using an ink jet printer that can improve the printing accuracy by eliminating the influence of wind and can increase the sharpness of printing. The purpose is to do.

[0007]

A printer using an inkjet printer according to the present invention accommodates an inkjet printer A that prints on a material 6 to be printed and a material to be printed 6 and at least the nozzles 1 of the inkjet printer A for printing. Closed print room 7 and closed print room 7
It is characterized by comprising a decompression device 8 for decompressing the inside.

[0008]

The object to be printed 6 and at least the nozzle 1 of the ink jet printer A are housed in the closed printing chamber 7, and printing is performed while the pressure inside the closed printing chamber 7 is reduced by the pressure reducing device 8. Even if the printed matter 6 travels at a high speed, air is rarely generated in the closed printing chamber 7 where the air is diluted and the air is diluted, and there is no possibility of being affected by the wind. The evaporation rate of the diluent of the ink is accelerated, the drying of the ink can be accelerated, and the bleeding of the ink can be prevented.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples. As the ink jet printer, any one such as a charge deflection type ink jet printer can be used. In the present invention, in particular, a large number (in some cases, up to several thousand) nozzles 1 are arranged in a row in a casing 11 It is preferable to use an inkjet printer in which a multi-nozzle type head A is formed as shown in FIG. The head A of this multi-nozzle type inkjet printer is arranged above the feeding device 18 which serves as a carrying table. The feeding device 18 is formed by a belt conveyor 20 which is driven and driven by a motor 19 such as a pulse motor, and the head A of the multi-nozzle type inkjet printer is arranged so that the parallel direction of the nozzles 1 is orthogonal to the traveling direction of the belt conveyor 20. It is arranged. In the embodiment shown in FIG. 2A, the gutter 5 is arranged diagonally below the head A, but the gutter 5 may be housed in the casing 11 of the head A.

FIG. 2B shows the basic structure of the charge deflection type ink jet printer.
Only one nozzle 1 contained therein is shown. In FIG. 2B, 12 is an oscillating electrode such as a piezoelectric element for vibrating the nozzle 1, 3 is a charging electrode, 4 is a deflection electrode, and the charging electrode 3 and the deflection electrode 4 are housed in the casing 11 of the head A. There is. The charging electrode 3 is provided corresponding to each nozzle 1 arranged in parallel in the head A, and the charging electrode 3 can also be formed as a pin electrode. And each nozzle 1 arranged in parallel in the head A
The ink reservoir 13 is connected to the ink reservoir 13
The ink 14 is supplied from the nozzle to the nozzle 1. In this case, when the ink 14 is supplied to the nozzle 1, it becomes the ink particles 2 by the action of the oscillation electrode 12 and is continuously ejected from the nozzle 1, and is ejected continuously from the nozzle 1. The ink particles 2 are selectively charged when passing through the charging electrode 3. That is, the charging electrode 3 is controlled to be turned on and off. When the charging electrode 3 is turned on, the ink particles 2 passing through the charging electrode 3 are charged, and when the charging electrode 3 is turned off, the charging electrode 3 is passed through. Do not charge the ink particles 2 to
The ink particles 2 are selectively charged. When each ink particle 2 passes between the deflection electrodes 4, the flight trajectory of the charged ink particle 2 is deflected and
The ink particles 2 that are not charged will go straight without being deflected, and the ink particles 2 whose flight path is deflected will be captured by the gutter 5 and collected in the ink reservoir 13 for reuse.
The ink particles 2 that travel straight without being deflected are not captured by the gutter 5 and reach the printed material 6 such as a printed wiring board.

As shown in FIG. 1, the head A for accommodating the nozzle 1 of the ink jet printer and the feeding device 18 are arranged in a closed printing chamber 7 formed by a closed box or the like. Further, a pressure reducing device 8 formed of a vacuum pump, a plate fan, or the like is connected to the.
An entrance 7a and an exit 7b that can be closed so as to keep airtightness are provided at the front and rear of the closed printing chamber 7, respectively, and the print substrate 6 to be printed such as a printed wiring board opens the entrance 7a and is fed to the feeding device 18. The printing material 6 which has been supplied and set, and printing has been completed opens the outlet 7b, and the feeding device 1
It can be taken out from 8.

Further, as the ink 14 used in the ink jet printer, a solvent diluting type thermosetting resin ink, a UV curing type resin ink and the like are generally used, and as the solvent, MEK, ethyl alcohol, methyl alcohol, butanol, 3 using an organic solvent such as acetone
The ink 14 is diluted in the range of 0 to 90 parts by weight. The main resin of the ink 14 is epoxy resin, acrylate resin, phenol resin, urea resin,
Thermosetting resins such as melamine resin and polyimide resin are used, but it is also possible to use thermoplastic resins such as vinyl acetate resin and acrylic resin. The resin is blended in the range of 5 to 50 parts by weight. As other solid content, 5 to 20 parts by weight of a colorant such as a pigment or a dye, a filler, and the like can be blended, and if necessary, a chargeability-imparting agent can be added in several parts by weight.

Therefore, when printing is performed on the surface of the printed material 6 such as a printed wiring board, the printed material 6 is conveyed to the belt conveyor 20 of the feeding device 18 as shown in FIG. 2A.
After being placed horizontally on the table as a table and set, the inside of the closed printing chamber 7 is decompressed by the decompression device 8. The degree of decompression depends on the performance of the decompression device 8, the decompression start time, the required energy,
It is appropriately set according to the required print quality and the like, and a range of 750 mmHg to 50 mmHg is preferable. In the charge-deflection type inkjet printer, if the charging voltage is high or the deflection voltage is high, the pressure reduction causes a state such as a spark. Therefore, it is necessary to set the degree of pressure reduction also in consideration of this.

Then, the belt conveyor 20 is driven by the motor 19.
Of the multi-nozzle type inkjet printer to pass the material 6 to be printed at a constant speed by running the same at a constant speed. At this time, all the nozzles 1 arranged in parallel in the head A From ink particles 2
Are continuously ejected, and some of the ink particles 2 ejected from each of the nozzles 1 are charged by controlling the charging electrode 3 to be turned on, and the flight trajectory is deflected by the deflecting electrode 4 so that the gutter 5 is discharged. To capture. Further, the other ink particles 2 are controlled so as not to be charged by controlling the charging electrode 3 so as not to be charged, and are moved straight so as not to be influenced by the deflection electrode 4, and the ink particles 2 thus moved straight reach the surface of the material 6 to be printed. Let In this way, by controlling the charging electrode 3 of each nozzle 1 on / off to selectively charge the ink particles 2 ejected from each nozzle 1, it is possible to select the ink particles 2 that reach the printed material 6. It is possible to select the position where the ink particles 2 are attached to the printed material 6, and the ink particles 2 are attached to the printed material 6 in this manner while moving the printed material 6 with respect to the head A by the feeding device 18. By selectively adhering them, it is possible to print with desired characters, symbols or patterns. That is, as shown in FIGS. 3A to 3F, the head A is moved while moving the printing object 6 in the arrow direction at a constant speed.
By selectively adhering the ink particles 2 ejected from each of the nozzles 1 to the surface of the material 6 to be printed, it is possible to perform printing with desired characters, symbols or patterns. The ink ejection diameter of each nozzle 1 is 30 to 15
The size of the ink dots adhered to the printing medium 6 is preferably set to 0 μm to 0.1 to 0.3 mm, and the oscillation frequency is preferably set to 20 to 200 kHz.

As described above, when printing with the ink jet printer, this printing is performed in the closed printing chamber 7
Since the pressure is reduced in the closed printing chamber 7 by the pressure reducing device 8, the feeding device 18
Thus, even if the printed material 6 travels at a high speed, wind is unlikely to be generated in the closed air chamber 4 in which the air is lean due to the reduced pressure, and printing can be performed without being affected by the wind. Therefore, the direction of flight of the ink particles 2 flying from the nozzles 1 in the head A to the printed material 6 is not affected by the wind, and the ink particles 2 arrive at the printed material 6 at the target accurate position and the accuracy is improved. It is possible to perform good printing. Further, the evaporation rate of the diluent of the ink 14 is accelerated in the closed printing chamber 7 in the depressurized state, so that the drying of the ink 14 adhering to the surface of the printed material 6 can be accelerated, and the diluent permeates. It is possible to prevent the ink 14 from bleeding on the printing object 6, and it is possible to improve the sharpness of printing.

In the embodiment shown in FIG. 2A, the print width of the head A of the multi-nozzle type ink jet printer (arrangement width of the nozzles 1) is made larger than the width of the object 6 to be printed. The printed matter 6 can be printed only by passing it under the head A once.
When the print width dimension of the head A is smaller than the width dimension of the printed material 6, the head A is fed to the printed material 6 by the feeding device 18.
By moving in the width direction orthogonal to the feed direction of the sheet, the substrate 6 is fed again under the head A,
It is possible to print. For example, the width of the substrate 6 is about 600 mm, and the print width of the head A is 50 m.
In the case of m, the head A is moved 12 times at right angles to the feeding direction of the printed material 6 to reciprocate the printed material 6 under the bed A, thereby printing on the entire surface of the printed material 6. You can When printing is performed while moving the head A at a right angle to the feeding direction of the printed material 6 in this way, the total travel distance of the printed material 6 that passes under the head A becomes very long. For example, when printing is performed while moving the head A 12 times as described above when the length of the printing material 1 in the feeding direction is 600 mm, the total distance traveled by the printing material 6 passing under the head A is 6
It becomes 00 mm × 12 = 7200 mm. Therefore, in this case, it is necessary to set the traveling speed of the material to be printed 6 to a high speed of about 100 m / min to improve the printing productivity. However, as described above, the closed printing chamber 7 is depressurized and wind is generated. Since it is difficult to do so, it is possible to prevent the influence of the wind even if the printed material 6 is sent at such a high speed.

Further, in the embodiment of FIG. 2A, the feeding device 1
Although the printing material 6 is sent at 8 and the printing material 6 is moved by moving the printing material 6 relative to the nozzle 1 of the inkjet printer, the nozzle 1 may be moved. Further, since the pressure inside the closed printing chamber 7 is reduced, it is preferable in that the ink 14 is easily discharged from the nozzle 1 and the load is reduced. On the contrary, it is difficult to stop the ink 14 in the nozzle 1. Therefore, the ink 14 is constantly discharged from the nozzle 1 as shown in FIG.
An inkjet printer of the type as shown in (b) is preferable. In this case, the path for collecting the ink 14 from the gutter 5 to the ink reservoir 13 needs to be depressurized at a higher vacuum level than in the closed printing chamber 7.

By performing printing in the closed printing chamber 7 in a reduced pressure state as described above, the evaporation rate of the diluent of the ink 14 is accelerated to accelerate the drying, and the ink 14 is covered by the penetration of the diluent. Since it is possible to prevent the printed matter 6 from bleeding, it is possible to widen the selection range of the solvent used as the diluent, and it is possible to select a safe solvent with less pollution. Further, according to the present invention, since the shape of the ink dot to be adhered to the printed material 6 becomes a perfect circle in this way, it is possible to perform printing with a stable image,
Furthermore, it is easy to print with a thick ink layer by overlapping printing of ink dots. In addition, since printing is performed in the closed printing chamber 7 in a depressurized state, the printing substrate of the printing object 6 is stable, and printing can be performed stably on the printing object 6 having various surface states and shapes. .
Further, it is possible to prevent fine ink particles from scattering and adhering to the surface of the printing material 6 as satellites, and the deflection is successful even if the ejection speed of the ink particles 2 from the nozzle 1 is slowed. Even when printing is performed so that the ink particles 2 overlap with each other, the material to be printed 6
It is possible to prevent the ink particles 2 from scattering on the surface of the ink, and to clean the printed surface.

[0019]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, an ink jet printer that prints on a material to be printed, a sealed printing chamber that accommodates the material to be printed and at least nozzles of the ink jet printer to perform printing, and depressurizes the sealed printing chamber. Since it is equipped with a decompression device, even if the material to be printed is traveling at high speed, air is dilute and the air is diluted, so it is difficult for wind to occur in the closed printing chamber, and printing can be performed without being affected by wind. The printing accuracy can be improved. Further, in the closed printing chamber under the reduced pressure, the evaporation rate of the ink diluent can be accelerated to accelerate the drying of the ink, and the ink can be prevented from bleeding and the printing can be performed clearly.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of the present invention.

2A and 2B show an embodiment of the present invention, in which FIG. 2A is a partial perspective view and FIG. 2B is a cross-sectional view of a head of a multi-nozzle type inkjet printer.

FIG. 3 shows a procedure in which printing is performed by a multi-nozzle type inkjet printer,
(A) thru | or (f) are some schematic plan views.

[Explanation of symbols]

 1 Nozzle 6 Printed material 7 Closed printing room 8 Pressure reducing device

Claims (1)

[Claims] 1. An ink jet printer for printing on a material to be printed, a closed printing chamber for containing and printing at least the nozzle of the material to be printed and an ink jet printer, and a decompression device for decompressing the closed printing chamber. A printing device using an inkjet printer, which is characterized in that