JPH05327174A - Printing to printed-wiring board - Google Patents

Abstract

PURPOSE:To make it possible to perform a printing on a printed-wiring board by an ink jet printer without a possibility that an adverse effect is exerted on the electrical characteristics of the board and to contrive to be profitable economically the printing. CONSTITUTION:Inorganic ion exchanger power bodies 2 are made to adhere on the surface of a printed-wiring board 1. Ink particles 10 are made to jet on these power bodies from an ink jet printer and a printing is performed on the board 1. The inorganic ion exchanger powder bodies 2, which are not adhered with the particles 10, are recovered from the surface of the board 1. Ions, such as an electrifying agent, in ink of the printer are trapped by an inorganic ion exchanger adhered on the surface of the board 1 and the ions in the ink can be prevented from acting on circuits on the board 1. The inorganic ion exchanger powder bodies, which are not adhered with the ink particles 10, among the inorganic ion exchanger powder bodies 2 on the surface of the board 1 are recovered add can be reused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method for marking printing on the surface of a printed wiring board.

[0002]

2. Description of the Related Art Generally, screen printing is used for marking and printing a product number, a lot number, a company symbol mark, a care mark, etc. on the surface of a printed wiring board. However, in the case of screen printing, it is necessary to make a screen plate, and even in the case of production in small lots and a large number of products, there is a problem in that the work efficiency becomes poor and the cost becomes high if such plate making is performed one by one.

Therefore, the applicant of the present invention has proposed to perform printing by printing on the surface of a printed wiring board using an ink jet printer. According to the inkjet printer, it is possible to print with arbitrary characters etc. according to the input data to the computer without using a plate. Moreover, the inkjet printer can print on the surface of the printed material like the wire dot printer. Since it can be printed without any impact and even if there is some unevenness on the surface, it is most suitable as a device for printing on a printed wiring board having a circuit formed on the surface.

As the ink jet printer, a well-known one which has been conventionally used is used.
FIG. 6 shows the principle of the charge deflection type inkjet printer. In FIG. 6, 11 is a nozzle provided with a piezo element 12, 13 is a charging electrode, 14 is a deflection electrode, 15 is a gutter,
Reference numeral 16 is a sensor, from the ink reservoir 17 to the nozzle 11
The ink 18 supplied to the nozzles 12 is ejected from the nozzles 12 as ink particles 10 by the action of the piezo element 12. Characters to be printed are divided into dots in a matrix, and each ink particle 10 is charged by a charging electrode 13 with a voltage proportional to the position information of each pixel. When passing through the space, it is deflected according to the amount of charge, reaches the surface of the printed wiring board 1, and printing can be performed with predetermined characters and the like. The ink particles 10 that are not used for printing are not charged by the charging electrode 13, go straight, are caught by the gutter 15, and are collected in the ink reservoir 17.

As described above, in a general charge-deflection type ink jet printer, since printing is performed by charging and deflecting ink particles, lithium ink, cyanate or the like is added to the ink as a charging agent. Ink specific resistance value is 800 Ωcm to 20
It is about 00 Ωcm. The charging agent is 0.1
About 5% by weight is blended.

[0006]

However, as described above, in the charge-deflection type ink jet printer, since the ink contains a charging agent such as lithium nitrate or cyanate, the ink contains ions, and therefore the ink jet printer has a problem. When printing is performed on the surface of the printed wiring board, the ions may act on the circuit of the printed wiring board to cause dielectric breakdown under high temperature and high humidity conditions. In addition, FIG.
As described above, a comb-shaped pattern 20 having a pattern width of 1 mm and a pattern interval d = 1.5 mm is formed on the surface of the printed wiring board, and a solder resist is applied on the comb-shaped pattern 20 to form a thickness of 10
A circuit protection film of μ is provided, the entire surface is printed on the circuit protection film by an ink jet printer, and a test is performed by continuously applying a voltage of DC100V for 500 hours under the conditions of 60 ° C. and 95% RH. 20
In some cases, migration occurs between the electrodes and the insulation between the electrodes of the comb pattern 20 cannot be ensured. Even if migration does not occur, the insulation resistance value between the comb patterns 20 is about 10 ¹³ to 10 ^{14 and} 10 ⁷ to 1
0 decreases to about ⁸ was achieved, there is a problem in securing the insulation. In addition, even in a place where ink does not adhere, the ink may scatter after adhering to the surface of the printed wiring board and adhere to the surroundings, or particles of a prescribed size (about 60 to 100 μ) may scatter from the nozzle. Then, the same problem occurs.

It is not necessary to use an ink containing a charging agent in an ink jet printer of a bubble jet type, a static control type, or a drop-on-mind type, which is not a charge-deflection type. Pigments and other additives include ionic ones, and as long as they are used in printed wiring boards, they cause more or less problems in terms of insulation.

The present invention has been made in view of the above points, and enables an inkjet printer to perform printing without fear of adversely affecting the electrical characteristics of a printed wiring board, and is economically advantageous. It is an object of the present invention to provide a method for printing on a printed wiring board.

[0009]

According to the method for printing on a printed wiring board of the present invention, a powder of an inorganic ion exchanger is attached to the surface of the printed wiring board, and ink particles are ejected from an inkjet printer onto the powder. To print,
It is characterized in that the powder of the inorganic ion exchanger that is not attached to the ink particles is recovered from the surface of the printed wiring board.

[0010]

[Function] Ions such as a charging agent in the ink of the ink jet printer are captured by the inorganic ion exchanger attached to the surface of the printed wiring board to prevent the ions in the ink from acting on the circuit of the printed wiring board. it can.
Further, among the inorganic ion exchanger powders on the surface of the printed wiring board, those not attached to the ink particles can be recovered and reused.

[0011]

EXAMPLES The present invention will be described in detail below with reference to examples. The printed wiring board 1 is created by providing a circuit with a copper foil pattern or the like on the surface of an insulating substrate. As the insulating substrate, a glass cloth or a glass non-woven fabric as a base material,
Paper or thermosetting resin-based or thermoplastic resin-based organic substrates such as epoxy resin substrates, phenol resin substrates, polyester resin substrates, Teflon resin substrates, etc. that use these in combination, inorganic substrates such as ceramic substrates, and other organic Any material such as one formed of an inorganic mixed material can be used. The surface of the printed wiring board 1 is covered with a circuit protective film such as a solder resist so as to cover the circuit, if necessary.

The inorganic ion exchanger is a substance capable of exchanging ions with the inorganic ion exchanger for trapping, and known ones disclosed in JP-A-59-170173 can be used. .. Specifically, those provided as "IXE" series by Toagosei Kagaku Kogyo Co., Ltd. can be used. This "IX
Among the "E" series, "IXE-100" (zirconium cation exchange type), "IXE-150" (zirconium cation exchange type), "IXE-200"
(Tin-based cation exchange type), "IXE-300"
(Antimony cation exchange type), "IXE-40
0 "(titanium-based cation exchange type)," IXE-60
Grades such as "0" (antimony and bismuth ion exchange type) are preferred. These inorganic ion exchangers are powders of extremely small particles having a specific gravity of about 5.5 and an average particle diameter of about 1 to 2 μ.

This inorganic ion exchanger has its powder 2 shown in FIG.
It is used by being attached to the surface of the printed wiring board 1 as shown in (a). When the powder 2 of the inorganic ion exchanger is attached to the surface of the printed wiring board 1, the powder 2 of the inorganic ion exchanger is mixed with a low boiling point organic solvent and dispersed to prepare a dispersion solution 21. As shown in FIG. 2, the coating tank 23 in which the coating felt 22 is drawn downward from the bottom portion.
The dispersion solution 21 is put in the inside so that the dispersion solution 21 permeates the coating felt 22, and the coating felt 2
The dispersion solution 21 is applied to the surface of the printed wiring board 1 by sending the printed wiring board 1 in a state of being in contact with the lower end of the printed wiring board 1. After the dispersion solution 21 in which the powder 2 of the inorganic ion exchanger is dispersed is applied as shown in FIG. 3A, the solvent of the dispersion solution 21 evaporates and scatters.
As shown in (b), only the powder 2 of the inorganic ion exchanger is attached and remains on the surface of the printed wiring board 1.

The inorganic ion exchanger powder 2 is sprayed onto the surface of the printed wiring board 1 by using a rotary feeder 25 or the like as shown in FIG. 4, so that the surface of the printed wiring board 1 is covered with the inorganic ion exchanger. The powder 2 can also be attached. The rotary feeder 25 is formed by a hopper 27 having a discharge port 26 on the lower surface and a supply roll 28 arranged so as to close the opening of the discharge port 6, and rotates the supply roll 28 in the arrow direction. When driven, the inorganic ion exchanger powder 2 is sent out from a minute gap between the supply roll 28 and the discharge port 6, and is sent to the surface of the printed wiring board 1 sent below the rotary feeder 25. Inorganic ion exchanger powder 2
Can be sprayed and attached. Further, FIG. 5 shows an electrostatic spraying device 30, and the spraying roll 3
The charging body 32a and the grounding body 32b are arranged in the unit 1, and the half of the spreading roller 31 in contact with the charging body 32a is charged with static electricity and the other half of the spreading roller 31 in contact with the grounding body 32b is not charged with static electricity. is there. And bucket 33
When the spraying roller 31 is rotationally driven while being in contact with the powder 2 of the inorganic ion exchanger inside, the powder 2 of the inorganic ion exchanger is electrostatically adsorbed on the surface of the spraying roller 31 where static electricity is charged. The electrostatic attraction of the spraying roller 31 is released from a place where the static electricity is no longer charged, and the spraying roller 31 is sprayed, and the sprayed inorganic ion exchange is performed on the surface of the printed wiring board 1 sent below the electrostatic spraying device 30. The body powder 2 can be attached.

On the other hand, inks used in ink jet printers include UV curable inks, thermosetting inks,
Any water-based ink, water-based thermosetting ink, solvent-based ink, or the like can be used. When the circuit protection film is formed by a solder resist, since the solder resist is generally a thermosetting type or a UV curing type, the ink is also of the same type as the U type.
V-curable ink and thermosetting ink are preferred. here,
An example of the composition of each of a UV-curable ink and a thermosetting ink for an inkjet printer, which contains an inorganic ion exchanger, is shown. (UV curable ink) -Charging agent (salts) 2 parts by weight-Dye, pigment (titanium oxide etc.) 10 parts by weight-Acrylate oligomer 35 parts by weight-Acrylate oligomer 15 parts by weight Photoinitiator 5 parts by weight Parts: MEK: 30 parts by weight Methyl alcohol: 20 parts by weight Others (Small amounts of surfactants, glycols, stabilizers, antioxidants, anti-corrosion agents, etc.) (thermosetting ink) -Charging agents (salts) … 0.2 parts by weight ・ Dye, pigment (titanium oxide etc.)… 10 parts by weight ・ Acrylic monomer… 35 parts by weight ・ Melamine resin… 15 parts by weight ・ Epoxy resin… 5 parts by weight ・ MEK… 30 parts by weight ・ Methyl alcohol 20 parts by weight ・ Others (a small amount of surfactants, glycols, stabilizers, antioxidants, anti-corrosion agents, etc.) These are diluted solvents (85 parts by weight of MEK and methyl). By dilution with alcohol 15 parts by weight mixed solvent of), specific resistance 1000 .OMEGA.cm, viscosity 4 cps (25 ° C.), are those that can be used to prepare the surface tension 30 dyn / cm. Of course, the ink is not limited to the above-exemplified inks, and the charging agent (salt) 0.0
01 to 10% by weight, dye or pigment 5 to 35% by weight, resin component (vinyl acetate, epoxy, acryl, phenol, melamine, etc.) 5 to 60% by weight, solvent 10 to 90% by weight, specific resistance 500. ~ 2500 Ωcm, viscosity 2-2
It is possible to use those generally prepared to 0 cps and a surface tension of 10 to 600 dyn / cm.

As the charging agent to be added to the ink,
It is preferable to use lithium nitrate (LiNO ₃ ). K
It is also possible to use a Na-based salt or the like. However, since a large amount of these may lead to deterioration of the original characteristics and performance of the ink, a cyanate may be used. Acid salts lack stability. For this,
Although not particularly limited, LiNO is used as the charging agent.
_It is preferable to use ₃ . When LiNO ₃ is used as the charging agent in this way, as the inorganic ion exchanger, a zirconium-based inorganic ion exchanger having a high ion exchange capacity for Li ions (for example, “IXE” manufactured by Toagosei Kagaku Kogyo Co., Ltd., supra) is used. -100 "," IXE-15 "
0 ") is preferably used.

As an ink jet printer,
The charge deflection type inkjet printer shown in FIG. 6 can be used. A specific example of conditions for printing on the surface of the printed wiring board 1 using this inkjet printer will be described. First, the piezo element 12 is vibrated at a frequency of 20 kHz, and the ink pressure is 3 Bar and the nozzle diameter is 6
The ink 18 having a specific resistance of 1000 Ωcm is ejected in a granular form from the 0 μ nozzle 11, and the charging electrode 13 charges the ink particles 10. The deflecting electrodes 14 are arranged at intervals of 8 mm and are applied with DC500V to 1000V, and the ink particles 10 fly about 8 cm while the deflecting electrodes 1 are moved.
4, the ink particles 10 are deflected and shaken in a width of 0 to 10 mm, and when the ink particles 10 reach the surface of the printed wiring board 1 as shown in FIG. 6, printing can be performed.
The non-charged ink particles 10 travel straight and are received by the gutter 15 and do not adhere to the printed wiring board 1. The ink particles 10 received by the gutter 15 are collected in the ink reservoir 17 and reused after being regenerated by stirring or adjusting the viscosity. Printing can be performed by fixing the nozzles 11 of the inkjet printer and moving the printed wiring board 1, but a method of moving the nozzles 11 may be used. Further, when high-speed printing (printing) is required, a multi-nozzle system in which a plurality of nozzles 11 are provided in parallel can be adopted. It is preferable to cover the area from the nozzle 11 to the surface of the printed wiring board 1 to be printed so that the flight of the ink particles 10 is not affected by the flow of air, but the ink attached to the printed wiring board 1 is dried. In order to accelerate bleeding and prevent bleeding and repelling, it is effective to send air to the air at a wind velocity of about 5 to 1000 cm / sec. In the present invention, the ink jet printer is not limited to the above-described charge deflection type, but the bubble jet type, the static control type, the drop type, etc.
It may be an on-mind type inkjet printer.

As shown in FIG. 1 (a), the printed wiring board 1 having the inorganic ion exchanger 2 adhered to the surface is printed by an ink jet printer, and the ink particles 10 are attached to the surface of the printed wiring board 1. Then, Fig. 1 (b)
As shown in FIG. 3, the inorganic ion exchanger powder 2 attached to the surface of the printed wiring board 1 is attached to the ink particles 10. Then, ions such as a charging agent contained in the ink particles 10 act on the circuit of the printed wiring board 1, but these ions are ion-exchanged and captured by the inorganic ion exchanger, and the ink particles 10 It is possible to prevent the ions contained in the ink from acting on the circuit, and it is possible to prevent the insulating property from being deteriorated by the action of the ions contained in the ink of the ink jet printer. As a result, even if the migration test shown in FIG. 7 is performed, the migration does not occur. The ion removal rate by the inorganic ion exchanger reaches 60 to 98%, and the ion exchange capacity of the inorganic ion exchanger is increased by heating. Therefore, the printed wiring board is heated to about 100 to 160 ° C after printing. It is effective to heat for about 10 to 30 minutes to enhance the ion trapping effect. Therefore, even when a solvent-type ink that does not originally require heat curing is used as the ink, it is preferable to heat the ink in order to improve the ion capturing efficiency.

When the ink particles are printed by the ink jet printer in this way to cure the ink particles 10,
Of the inorganic ion-exchanger powder 2 on the surface of the printed wiring board 1, the one adhered to the ink particles 10 is the ink particles 10.
The inorganic ion-exchanger powder 2 not adhered to the ink particles 10 is fixed to the printed wiring board 1.
The surface is free. Therefore, by brushing or sucking, the free inorganic ion exchanger powder 2 can be removed from the surface of the printed wiring board 1 and recovered as shown in FIG. 1 (c). The inorganic ion exchanger powder 2 can be reused. Inorganic ion exchangers are generally expensive, and it is economically very advantageous to recover and reuse those unused for ion exchange.

By the electrostatic transfer method (so-called Xerox), the inorganic ion exchanger powder 2 is formed on the surface of the printed wiring board 1 only in the portion to be printed by the ink jet printer.
It is also possible to attach. The inorganic ion exchanger powder 2 is made to coincide with the position where the ink particles 10 are adhered when the ink particle is printed by an inkjet printer.
The work of recovering is unnecessary.

[0021]

As described above, according to the present invention, the powder of the inorganic ion exchanger is adhered to the surface of the printed wiring board, and the ink particles are ejected from the ink jet printer onto the surface of the printed wiring board to perform the printing. Ions such as charging agents in the ink of the inkjet printer are captured by the inorganic ion exchanger attached to the surface of the printed wiring board,
It is possible to prevent ions in the ink from acting on the circuit of the printed wiring board, and it is possible to perform printing with an inkjet printer without the possibility of adversely affecting the electrical characteristics of the printed wiring board. Further, since the inorganic ion exchanger powder not adhered to the ink particles is collected from the surface of the printed wiring board, the inorganic ion exchanger powder on the surface of the printed wiring board is adhered to the ink particles. Those that are not available can be recovered and reused, which is economically advantageous.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention (a),
(B), (c) is some expanded sectional views.

FIG. 2 is a schematic view showing an example of an apparatus for applying a powder of an inorganic ion exchanger used in the present invention.

FIG. 3 shows the work of attaching the powder of the above inorganic ion exchanger to the printed wiring board, and (a) and (b) are partially enlarged cross-sectional views.

FIG. 4 is a schematic view showing another example of an apparatus for applying a powder of an inorganic ion exchanger used in the present invention.

FIG. 5 is a schematic view showing still another example of an apparatus for applying a powder of an inorganic ion exchanger used in the present invention.

FIG. 6 is a schematic diagram showing the principle of an inkjet printer.

FIG. 7 is a schematic diagram showing a comb-shaped pattern used for an electromigration test.

[Explanation of symbols]

 1 Printed Wiring Board 2 Inorganic Ion Exchanger Powder 10 Ink Particles

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 8, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

On the other hand, inks used in ink jet printers include UV curable inks, thermosetting inks,
Any water-based ink, water-based thermosetting ink, solvent-based ink, or the like can be used. When the circuit protection film is formed by a solder resist, since the solder resist is generally a thermosetting type or a UV curing type, the ink is also of the same type as the U type.
V-curable ink and thermosetting ink are preferred. here,
An example of the composition of each of a UV-curable ink and a thermosetting ink for an inkjet printer, which contains an inorganic ion exchanger, is shown. (UV curable ink) -Charging agent (salts) 2 parts by weight-Dye, pigment (titanium oxide etc.) 10 parts by weight-Acrylate oligomer 35 parts by weight-Acrylate oligomer 15 parts by weight Photoinitiator 5 parts by weight Parts: MEK: 30 parts by weight Methyl alcohol: 20 parts by weight Others (Small amounts of surfactants, glycols, stabilizers, antioxidants, anti-corrosion agents, etc.) (thermosetting ink) -Charging agents (salts) … 0.2 parts by weight ・ Dye, pigment (titanium oxide etc.)… 10 parts by weight ・ Acrylic monomer… 35 parts by weight ・ Melamine resin… 15 parts by weight ・ Epoxy resin… 5 parts by weight ・ MEK… 30 parts by weight ・ Methyl alcohol 20 parts by weight ・ Others (a small amount of surfactants, glycols, stabilizers, antioxidants, anti-corrosion agents, etc.) These are diluted solvents (85 parts by weight of MEK and methyl). By dilution with alcohol 15 parts by weight mixed solvent of), specific resistance 1000 .OMEGA.cm, viscosity 4 cps (25 ° C.), are those that can be used to prepare the surface tension 30 dyn / cm. Of course, the ink is not limited to the above-exemplified inks, and the charging agent (salt) 0.0
01 to 10% by weight, dye or pigment 5 to 35% by weight, resin component (vinyl acetate, epoxy, acryl, phenol, melamine, etc.) 5 to 60% by weight, solvent 10 to 90% by weight, specific resistance 500. ~ 2500 Ωcm, viscosity 2-2
It is possible to use those generally prepared to 0 cps and a surface tension of 15 to 50 dyn / cm.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

As an ink jet printer,
The charge deflection type inkjet printer shown in FIG. 6 can be used. A specific example of conditions for printing on the surface of the printed wiring board 1 using this inkjet printer will be described. First, the piezo element 12 is vibrated at a frequency of 20 kHz, and the ink pressure is 3 Bar and the nozzle diameter is 6
The ink 18 having a specific resistance of 1000 Ωcm is ejected in a granular form from the 0 μ nozzle 11, and the charging electrode 13 charges the ink particles 10. The deflection electrodes 14 are arranged at intervals of 8 mm and are applied with DC500V to 8kV ,
The ink particles 10 are deflected and shaken by the deflection electrode 14 in a width of 0 to 10 mm while flying for about 8 cm, and the ink particles 10 reach the surface of the printed wiring board 1 as shown in FIG. 6 to perform printing. be able to. The non-charged ink particles 10 travel straight and are received by the gutter 15 and do not adhere to the printed wiring board 1. The ink particles 10 received by the gutter 15 are collected in the ink reservoir 17 and reused after being regenerated by stirring or adjusting the viscosity. Printing can be performed by fixing the nozzles 11 of the inkjet printer and moving the printed wiring board 1, but a method of moving the nozzles 11 may be used. Further, when high-speed printing (printing) is required, a multi-nozzle system in which a plurality of nozzles 11 are provided in parallel can be adopted. Ink particles 1 are provided between the nozzle 11 and the surface of the printed wiring board 1 to be printed.
It is preferable to cover so that the flight of 0 is not affected by the flow of air, but in order to speed up the drying of the ink adhering to the printed wiring board 1 and prevent bleeding and repelling, air rectification is 5 to 1000 cm. It is effective to send at a wind speed of about / sec. In the present invention, the ink jet printer is not limited to the above-described charge deflection type, but the bubble jet type, the static control type, the drop type, etc.
It may be an on-mind type inkjet printer.

Claims (1)

[Claims] 1. A method for depositing an inorganic ion exchanger powder on a surface of a printed wiring board, ejecting ink particles from the inkjet printer onto the surface of the printed wiring board to perform printing, and A method for printing on a printed wiring board, characterized in that powder is collected from the surface of the printed wiring board.