JP2004025700A - Inkjet printing device for substrate, and printing process therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printing device for substrates which is suitable for limited production with a wide variety and can form thick coating films, and to provide a printing process therefor. <P>SOLUTION: In the inkjet printing device for printed wiring boards of this invention, in applying an ink 6 onto the printed wiring board 1, a prescribed voltage is impressed to an ink liquid fed into a print head 2. A coloring matter composition in the ink liquid to which the voltage is impressed coheres, and the ink liquid becomes the ink 6 of a high concentration and a high viscosity. The ink 6 which becomes the high concentration and high viscosity flies horizontally to the ground surface and is applied onto the printed wiring board 1 in a normal status to the ground surface. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inkjet printing apparatus for a substrate for printing on a substrate, and more particularly to an inkjet printing apparatus for a printed wiring board suitable for printing on a printed wiring board and a printing method thereof.
[0002]
[Prior art]
On the surface of the printed wiring board, a component layout diagram, component names, etc. are printed with numbers, lines, symbols, etc. (so-called marking printing), and when the printed wiring board is checked or when there is a failure, the component placement or components are printed. It is easy to understand at a glance what it looks like.
[0003]
As such marking printing on a printed wiring board, there is silk screen printing. In the silk screen printing, a quick-drying ink liquid can be used, so that the coating film can be applied thickly, the concealing power and the abrasion resistance are strong, and the coating film can be easily laminated due to its high viscosity. Also, in the production of a printed wiring board, when a resist film is to be formed at a place where the pitch is narrow, a substitute resist film may be formed by laminating the coating film instead of forming the resist film with solder. is there. At this time, silk screen printing also has the advantage that the formation of a substitute resist film can be facilitated because the coating films are easily laminated.
[0004]
However, in silk screen printing, a screen plate is required for each specification to be manufactured, and the amount of ink liquid used is inefficient because it is necessary to apply ink liquid to the entire surface of the substrate. It is unsuitable for printing applications on printed wiring boards, which tend to produce a small variety of products.
[0005]
Therefore, conventionally, a method of performing marking printing on a printed circuit board by using inkjet printing such as a thermal method, a piezo method, or a continuous method (hereinafter, referred to as conventional ink-jet printing for a printed circuit board) is well known. According to the conventional inkjet printing for a printed wiring board, a screen plate is not required, and the ink liquid can be made to fly only to an appropriate place on demand, so that it can be said that the printing is suitable for high-mix low-volume production.
[0006]
[Problems to be solved by the invention]
However, conventional inkjet printing for printed wiring boards is suitable for high-mix low-volume production, but due to the necessity of jetting ink due to its structure, it is not possible to increase the concentration of the ink liquid, resulting in low viscosity. However, there is a problem that the drying of the coating film becomes slow, and the coating film becomes thin and weak in abrasion resistance.
[0007]
In addition, it was difficult to form a coating film due to the low viscosity of the ink liquid, and it was difficult to form a substitute resist film.
[0008]
As described above, it is desired that printing on a printed wiring board is suitable for high-mix low-volume production and can form a thick coating film. Such a problem is not limited to a printed wiring board.For example, a substrate such as a thin film formed of plastic, metal, glass, ceramic, or the like, which has not been subjected to a surface treatment for fixing the ink. Applies to
[0009]
The present invention has been made in order to solve the problems of the prior art, and is an ink jet printing apparatus for a substrate which is suitable for high-mix low-volume production and can form a thick coating film, and particularly an ink jet printing apparatus for a printed wiring board. And a printing method thereof.
[0010]
[Means for Solving the Problems]
An ink jet printing apparatus for a substrate for printing on a substrate that has not been subjected to surface treatment for fixing the ink, wherein a predetermined voltage is applied to the supplied ink liquid to aggregate the ink liquid, A print head for causing the ink to fly later, wherein the print head causes the ink to fly horizontally with respect to the ground, and the substrate has a printed surface of the substrate oriented perpendicular to the ground. Is to be printed.
[0011]
In the ink jet printing apparatus for a substrate according to the present invention, a predetermined voltage is applied to the ink liquid supplied to the print head when the ink is applied onto a substrate that has not been subjected to a surface treatment for fixing the ink. In the ink liquid to which the voltage is applied, the dye components in the ink liquid are aggregated, and the ink liquid has high density and high viscosity. In this way, the highly concentrated and highly viscous ink flies from the print head and is applied to the substrate.
[0012]
The print head also causes the ink to fly horizontally with respect to the ground. As described above, in order to fly high-density and high-viscosity ink, even when printing is performed with the printed surface of the substrate vertical (vertical) to the ground, printing is performed in place without dripping. be able to.
[0013]
In this way, high-density and high-viscosity ink can be jetted in inkjet printing that can be produced in a large variety of small quantities. Marking printing with strong concealing power and abrasion resistance can be performed. Since the surface treatment step of the substrate is unnecessary, the devices, materials and time required for the surface treatment step can be reduced. Further, since the coating films can be easily laminated, a substitute resist film can be easily formed.
[0014]
In addition, although a predetermined drying time is conventionally required for fixing the ink, the drying time is shorter by flying high-concentration and high-viscosity ink. Even if it becomes unnecessary or a drying device is used separately, fixing can be achieved in a short time, and the space of each device can be saved.
[0015]
Further, by printing the printed wiring board in the vertical direction, it is possible to save the space of the drying device for fixing the ink. In addition, by printing the substrate in the vertical direction, the ink can be similarly ejected from either side of the substrate. In the case of printing on both sides of the substrate, conventionally, a step of first printing on one side, drying, printing the back side, and drying again was required.In the present invention, both sides are simultaneously printed and dried. Can also be completed at once. Therefore, since both sides can be printed and dried at the same time, the time required for the printing step can be greatly reduced.
[0016]
In addition, a substrate that has not been subjected to surface treatment for fixing an ink is a substrate on which ink generally does not easily penetrate into the substrate, such as a thin film formed of plastic, metal, glass, ceramic, or the like. And the like, and a printed wiring board, etc., and the inkjet printing apparatus of the present invention performs marking printing or the like without performing surface treatment on such a substrate.
[0017]
Preferably, the apparatus further comprises a transport device for transporting the substrate with the printed surface of the substrate oriented perpendicular to the ground.
[0018]
In this case, the substrate to be printed is transported with the printing surface directed perpendicular to the ground, and printing is performed in this state. Thus, the process of marking and printing on the substrate can be smoothly introduced into the overall flow work, and the work can be performed more efficiently.
[0019]
Preferably, the ink liquid is configured to be a thermosetting ink liquid.
[0020]
In conventional inkjet printing, only a low-viscosity ink liquid can be used, but in order to shorten the drying time, a low-viscosity and quick-drying UV curable ink liquid is used, and drying is performed by irradiating ultraviolet rays after applying the ink. The time was shortened. In the apparatus of the present invention, since the viscosity of the ink liquid used does not depend on the viscosity, the ink liquid having high viscosity can be used as the ink liquid before aggregation.
[0021]
In the case of a printed wiring board or the like, the board may be washed after marking printing. In some cases, electronic components and the like are mounted on a substrate. In particular, in such a case, by using a thermosetting ink liquid as the high-viscosity ink liquid, chemical resistance at the time of cleaning the substrate, etc., and scratch resistance at the time of mounting electronic components on the substrate, etc. Can be increased.
[0022]
Preferably, the substrate is configured to be a printed wiring board.
[0023]
A printed wiring board can be said to be a board that is particularly desired for high-mix low-volume production. Furthermore, chemical resistance and abrasion resistance are particularly desired by washing, attaching electronic parts, and the like.
[0024]
Therefore, it is possible to perform marking printing with high concealing power and abrasion resistance, easily form a substitute resist film, and save space in each device and greatly reduce the time required for the printing process. It is particularly effective to use the substrate inkjet printing apparatus of the present invention for marking printing on a printed wiring board.
[0025]
Further, the inkjet printing method for a printed wiring board according to the present invention is an inkjet printing method for printing on a substrate that has not been subjected to a surface treatment for fixing ink, wherein the printing surface of the substrate is grounded. In this state, a predetermined voltage is applied to the ink liquid to cause the ink liquid to aggregate, and the ink after the aggregation is caused to fly horizontally to the ground for printing. .
[0026]
In the inkjet printing method for a substrate according to the present invention, a predetermined voltage is applied to the ink liquid when the ink is applied onto a substrate that has not been subjected to a surface treatment for fixing the ink. In the ink liquid to which the voltage is applied, the dye components in the ink liquid are aggregated, and the ink liquid has high density and high viscosity. Thus, the highly concentrated and highly viscous ink flies horizontally with respect to the ground. On the other hand, the substrate is oriented perpendicular to the ground. Therefore, the ink that has flown horizontally with respect to the ground is applied on a substrate that is perpendicular to the ground.
[0027]
In this way, high-density and high-viscosity ink can be jetted in inkjet printing that can be produced in a large variety of small quantities. Marking printing with strong concealing power and abrasion resistance can be performed. Since the surface treatment step of the substrate is unnecessary, the devices, materials and time required for the surface treatment step can be reduced. Further, since the coating films can be easily laminated, a substitute resist film can be easily formed.
[0028]
In addition, although a predetermined drying time is conventionally required for fixing the ink, the drying time is shorter by flying high-concentration and high-viscosity ink. Even if it becomes unnecessary or a drying device is used separately, fixing can be achieved in a short time, and the space of each device can be saved.
[0029]
Further, by printing the printed wiring board in the vertical direction, it is possible to save the space of the drying device for fixing the ink. In addition, by printing with the substrate oriented vertically, the ink can also be caused to fly from either side of the substrate. In the case of printing on both sides of the substrate, conventionally, a step of first printing on one side, drying, printing the back side, and drying again was required.In the present invention, both sides are simultaneously printed and dried. Can also be completed at once. Therefore, since both sides can be printed and dried at the same time, the time required for the printing step can be greatly reduced.
[0030]
In addition, a substrate that has not been subjected to surface treatment for fixing an ink is a substrate on which ink generally does not easily penetrate into the substrate, such as a thin film formed of plastic, metal, glass, ceramic, or the like. And the like, and a printed wiring board, etc., and the inkjet printing apparatus of the present invention performs marking printing or the like without performing surface treatment on such a substrate.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the embodiments described below, an example is shown in which a printed wiring board is used as a substrate that has not been subjected to a surface treatment for fixing ink. However, the present invention is not limited to this. To be printed on a substrate that does not easily penetrate into the substrate, for example, a substrate such as a thin film formed of plastic, metal, glass, ceramic, and the like, and a printed wiring board without performing surface treatment. Is possible.
[0032]
A first embodiment of the present invention will be described. FIG. 1 is a partial schematic view of a printed circuit board printing apparatus according to a first embodiment of the present invention.
[0033]
The printing apparatus for a printed wiring board according to the first embodiment of the present invention is an inkjet printing apparatus for a printed wiring board for printing on the printed wiring board 1, and applies a predetermined voltage to the supplied ink liquid 6L. The print head 2 has a print head 2 for applying and aggregating the ink liquid 6L and flying the ink 6 after the aggregation, the print head 2 flying the ink 6 horizontally with respect to the ground, The printed wiring board 1 is printed with the printed surface of the printed wiring board 1 oriented perpendicular to the ground.
[0034]
As shown in FIG. 1, the printing apparatus main body includes a printer main body 3 for holding the printed wiring board 1 in a state perpendicular to the ground, and a print head 2 on the board mounting surface of the printer main body 3. A three-axis mobile unit 4 (X-axis mobile unit 4x, Y-axis mobile unit 4y, Z-axis mobile unit 4z) for performing three-dimensional movement, and a control unit (not shown) for controlling the three-axis mobile unit 4; It is configured to include a panel unit 5 for inputting an instruction for printing or the like with a button or the like and displaying and informing a printing state or the like, and a communication unit (not shown) for receiving print data.
[0035]
The shape and position of the marking and the like by the CAD and the scanner are converted into data by a computer and transmitted to the printing apparatus via the communication unit. The control unit moves the print head 2 three-dimensionally by moving the three-axis moving body 4 based on the transmitted data. Then, by printing an appropriate amount of the ink 6 from the print head 2 at an appropriate position horizontally on the ground, marking printing is performed on the printed wiring board 1. The user operates a button or the like of the panel unit 5 while checking a printing state or the like on a display or the like of the panel unit 5 so as to cause the printing apparatus to perform the printing as described above.
[0036]
In the ink jet printing apparatus for a printed wiring board in FIG. 1, when applying the ink 6 on the printed wiring board 1, a predetermined voltage is applied to the ink liquid 6L.
FIG. 2 is a schematic sectional view showing a structure of a print head in the printing apparatus for a printed wiring board in FIG.
[0037]
As shown in FIG. 2, the print head 2 temporarily stores 6 L of the ink liquid in the print head 2 and causes the ink to be ejected from the ink ejection unit 21, and the ink liquid 6 L stored in the ink storage tank 21. A charging electrode 22, a counter electrode 23 disposed opposite to the charging electrode 22, and an eject electrode 24 provided at an ink ejection portion of the ink storage tank 21. Of the print head.
[0038]
An appropriate amount of ink liquid 6L is supplied to the ink storage tank 21 from the ink liquid 6L stored in an ink storage tank (not shown) provided outside the print head 2. Further, the ink storage tank and the ink liquid 6L in the ink storage tank 21 may be circulated.
[0039]
The ink liquid 6L contains a chargeable component. The chargeable component is mainly composed of a pigment component of the ink such as a pigment and a dye. A predetermined voltage is applied between the charging electrode 22 and the counter electrode 23, and the charging electrode 22 applies the voltage to the ink liquid 6L. That is, the ink liquid 6L is charged to the opposite electrode 23 at the same potential as the charged electrode 22. Here, the voltage applied to the charging electrode 22 is preferably determined in consideration of the viscosity of the ink liquid, the characteristics of a chargeable component, the printing speed, and the like.
[0040]
The charged ink liquid 6 </ b> L is aggregated in the ink ejection part of the ink storage tank 21, that is, in the vicinity of the eject electrode 24 by the electric field (arrow in FIG. 2) generated between the charging electrode 22 and the counter electrode 23. At this time, in the ink liquid 6L, moisture in the ink liquid is removed, and the pigment component (that is, a chargeable component) is aggregated to form the high-concentration and high-viscosity ink 6. The eject electrode 24 applies a pulse voltage to the aggregated ink 6. The ink 6 to which the pulse voltage has been applied flies from the ink ejection portion of the ink storage tank 21 and is applied onto the printed wiring board 1. Here, the voltage applied to the eject electrode 24 is usually higher than the voltage applied to the charging electrode 22, and is preferably determined in consideration of the surface tension of the ink 6, the characteristics of the chargeable component, and the like.
[0041]
Each control such as the flow of the ink liquid, the ink liquid concentration, and the setting of each voltage is performed by a control unit.
[0042]
As described above, in ink-jet printing capable of producing a large variety of small-quantity products, the high-density and high-viscosity ink 6 can be caused to fly from the print head 2. In addition, marking printing with high scratch resistance can be performed. Further, since the coating films can be easily laminated, a substitute resist film can be easily formed. Further, in order to cause such a high-density and high-viscosity ink 6 to fly horizontally from the print head 2, even if printing is performed with the printed surface of the substrate vertical (vertical) with respect to the ground, liquid dripping occurs. It can be printed in place without doing it.
[0043]
In addition, a predetermined drying time is conventionally required for fixing the ink. However, since the drying time is shortened by flying the high-concentration and high-viscosity ink 6, the drying device provided in the printing apparatus is used. Can be eliminated, and even if a drying device is used separately, fixing can be achieved in a short time, and the space of each device can be saved.
[0044]
The ink liquid 6L used in the present embodiment is configured to be a thermosetting ink liquid.
[0045]
In conventional inkjet printing for printed wiring boards, only low-viscosity ink liquids can be used.However, in order to shorten the drying time, a quick-drying UV curable ink is used. The time was shortened. In the printing apparatus for a printed wiring board according to the present embodiment, since the viscosity of the ink liquid to be used does not depend on the viscosity of the ink liquid to be used, a high-viscosity ink liquid can be used as the ink liquid 6L before aggregation. By using a thermosetting ink liquid as the high-viscosity ink liquid 6L, the chemical resistance at the time of cleaning the printed wiring board 1 and the scratch resistance at the time of mounting electronic components on the printed wiring board and the like are improved. Can be enhanced.
[0046]
In this embodiment, there is no problem even if the ink liquid 6L other than the thermosetting ink liquid such as the UV curable ink liquid is used, and it is needless to say that it is enough to solve the above-mentioned problem. .
[0047]
Next, a second embodiment of the present invention will be described. FIG. 3 is a partial schematic view of a printed circuit board printing apparatus according to a second embodiment of the present invention. Portions having the same configuration as in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0048]
The present embodiment is different from the first embodiment in that the printed wiring board 1 further includes a transport device for transporting the printed surface of the printed wiring board 1 in a state where the printed surface is directed perpendicular to the ground, and The printed wiring board 1 is to be conveyed in a state where the printing surface is oriented perpendicular to the ground.
[0049]
As shown in FIG. 3, the printing apparatus for a printed wiring board according to the present embodiment includes a print head 2a, a printer main body 3a including a three-axis moving body for moving the print head 2a three-dimensionally, and a printer or the like. It includes a panel unit (not shown) for inputting an instruction with a button or the like and displaying and informing a printing state or the like, and a communication unit (not shown) for receiving print data. Further, as a transport device, a holder 7 for holding the printed wiring board 1 in a state where the printed surface of the printed wiring board 1 is perpendicular to the ground, and for transporting the printed wiring board 1 held by the holder 7. And a control unit (not shown) for controlling the movement of the holder 7 and the print head 2.
[0050]
The holder 7 holds the printed wiring board 1 and is transported by the transport path 8. When the holder 7 holding the printed wiring board 1 is conveyed to the position of the printer main body 3a, the printer main body 3a controls the three-axis movable body of the printer main body 3a based on data from the communication section to perform printing. Marking printing is performed by moving the head 2a and causing the ink 6 to fly at an appropriate position. The structure of the print head 2a is similar to that of FIG. 2 described in the first embodiment.
[0051]
Thereby, the process of marking and printing on the printed wiring board 1 can be smoothly introduced into the overall flow work, and the work can be performed more efficiently.
[0052]
In the present embodiment, as shown by the broken line in FIG. 3, the printer further includes two printer main bodies 3b opposed to the printer main body 3a and a print head 2b attached to the printer main body 3b.
[0053]
In the present embodiment, by transporting the printed wiring board 1 vertically, the ink 6 can be caused to fly from either side of the printed wiring board 1 in the same manner. In the case of performing marking printing on both sides of the printed wiring board 1, in the conventional method, first, a step of printing on one side, drying, printing the back side, and drying again is required. However, in the present embodiment, both sides are printed. And drying can be completed at the same time. As described above, since both sides can be printed and dried at the same time, the time required for the marking printing step can be significantly reduced.
[0054]
The ink liquid 6L used in the present embodiment is also configured to be a thermosetting ink liquid, and has the same effects as described in the first embodiment. May be used.
[0055]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the inkjet printing apparatus for printed wiring boards which concerns on this invention, since high-density and high-viscosity ink can be made to fly in inkjet printing which can produce many kinds and small quantities, while being suitable for many kinds and small quantities, printed wiring Marking printing with strong hiding power and abrasion resistance can be performed on the substrate. Further, since the coating films can be easily laminated, a substitute resist film can be easily formed.
[0056]
In addition, although a predetermined drying time is conventionally required for fixing the ink, the drying time is shorter by flying high-concentration and high-viscosity ink. Even if it becomes unnecessary or a drying device is used separately, fixing can be achieved in a short time, and the space of each device can be saved.
[Brief description of the drawings]
FIG. 1 is a partial schematic view of a printing apparatus for a printed wiring board according to a first embodiment of the present invention.
FIG. 2 is a schematic sectional view showing a structure of a print head in the printing apparatus for a printed wiring board of FIG. 1;
FIG. 3 is a partial schematic view of a printed circuit board printing apparatus according to a second embodiment of the present invention.
[Explanation of symbols]
1: printed wiring board 2: print head 6: ink

Claims (5)

A substrate inkjet printing apparatus for printing on a substrate that has not been subjected to surface treatment for ink fixing,
A print head for applying a predetermined voltage to the supplied ink liquid to aggregate the ink liquid, and to fly the ink after the aggregation,
The ink jet printing apparatus for a substrate, wherein the print head causes the ink to fly horizontally with respect to the ground, and the substrate is printed with a printed surface of the substrate oriented perpendicular to the ground. . 2. The inkjet printing apparatus for a substrate according to claim 1, further comprising a transport device configured to transport the printed surface of the substrate with the printed surface directed perpendicular to the ground. The inkjet printing apparatus for a substrate according to claim 1, wherein the ink liquid is a thermosetting ink liquid. The said board | substrate is a printed wiring board, The inkjet printing apparatus for boards in any one of Claims 1-3 characterized by the above-mentioned. An inkjet printing method on a substrate for printing on a substrate that has not been subjected to surface treatment for ink fixing,
While the printed surface of the substrate is oriented perpendicular to the ground, a predetermined voltage is applied to the ink liquid to coagulate the ink liquid, and the coagulated ink flies horizontally to the ground. An ink-jet printing method on a substrate, characterized by performing printing.

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